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<meta name="theme-color" content="#b31b1b">  <title>Search | arXiv e-print repository</title> <script defer src="https://static.arxiv.org/static/base/1.0.0a5/fontawesome-free-5.11.2-web/js/all.js"></script> <link rel="stylesheet" href="https://static.arxiv.org/static/base/1.0.0a5/css/arxivstyle.css" /> <script type="text/x-mathjax-config"> MathJax.Hub.Config({ messageStyle: "none", extensions: ["tex2jax.js"], jax: ["input/TeX", "output/HTML-CSS"], tex2jax: { inlineMath: [ ['$','$'], ["\$","\$"] ], displayMath: [ ['$$','$$'], ["\\[","\\]"] ], processEscapes: true, ignoreClass: '.*', processClass: 'mathjax.*' }, TeX: { extensions: ["AMSmath.js", "AMSsymbols.js", "noErrors.js"], noErrors: { inlineDelimiters: ["$","$"], multiLine: false, style: { "font-size": "normal", "border": "" } } }, "HTML-CSS": { availableFonts: ["TeX"] } }); </script> <script src='//static.arxiv.org/MathJax-2.7.3/MathJax.js'></script> <script 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<button class="button is-small is-link">Go</button> </div> </div> </form> </div> </div> <nav class="pagination is-small is-centered breathe-horizontal" role="navigation" aria-label="pagination"> <a href="" class="pagination-previous is-invisible">Previous </a> <a href="/search/?searchtype=author&query=Pradhan%2C+K&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Pradhan%2C+K&start=0" class="pagination-link is-current" aria-label="Goto page 1">1 </a> </li> <li> <a href="/search/?searchtype=author&query=Pradhan%2C+K&start=50" class="pagination-link " aria-label="Page 2" aria-current="page">2 </a> </li> </ul> </nav> <ol class="breathe-horizontal" start="1"> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2411.06130">arXiv:2411.06130</a> <span> [<a href="https://arxiv.org/pdf/2411.06130">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Medical Physics">physics.med-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Glucose Sensing Using Pristine and Co-doped Hematite Fiber-Optic sensors: Experimental and DFT Analysis </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Pattanayak%2C+N">Namrata Pattanayak</a>, <a href="/search/physics?searchtype=author&query=Das%2C+P">Preeti Das</a>, <a href="/search/physics?searchtype=author&query=Sahoo%2C+M+R">Mihir Ranjan Sahoo</a>, <a href="/search/physics?searchtype=author&query=Panda%2C+P">Padmalochan Panda</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+M">Monalisa Pradhan</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+K">Kalpataru Pradhan</a>, <a href="/search/physics?searchtype=author&query=Nayak%2C+R">Reshma Nayak</a>, <a href="/search/physics?searchtype=author&query=Patnaik%2C+S+K">Sumanta Kumar Patnaik</a>, <a href="/search/physics?searchtype=author&query=Tripathy%2C+S+K">Sukanta Kumar Tripathy</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2411.06130v1-abstract-short" style="display: inline;"> Glucose monitoring plays a critical role in managing diabetes, one of the most prevalent diseases globally. The development of fast-responsive, cost-effective, and biocompatible glucose sensors is essential for improving patient care. In this study, a comparative analysis is conducted between pristine and Co-doped hematite samples, synthesized via the hydrothermal method, to evaluate their structu… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.06130v1-abstract-full').style.display = 'inline'; document.getElementById('2411.06130v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2411.06130v1-abstract-full" style="display: none;"> Glucose monitoring plays a critical role in managing diabetes, one of the most prevalent diseases globally. The development of fast-responsive, cost-effective, and biocompatible glucose sensors is essential for improving patient care. In this study, a comparative analysis is conducted between pristine and Co-doped hematite samples, synthesized via the hydrothermal method, to evaluate their structural, morphological, and optical properties. The glucose sensing performance of both samples is assessed using a fiber-optic evanescent wave (FOEW) setup. While the sensitivity remains comparable for both pristine and Co-doped hematite, a reduction in the Limit of Detection (LoD) is observed in the Co-doped sample, suggesting enhanced interactions with glucose molecules at the surface. To gain further insights into the glucose adsorption mechanisms, Density Functional Theory (DFT) calculations are performed, revealing key details regarding charge transfer, electronic delocalization, and glucose binding on the hematite surfaces. These findings highlight the potential of Co-doped hematite for advanced glucose sensing applications, offering a valuable synergy between experimental and theoretical approaches for further exploration in biosensing technologies. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2411.06130v1-abstract-full').style.display = 'none'; document.getElementById('2411.06130v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 9 November, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2405.08829">arXiv:2405.08829</a> <span> [<a href="https://arxiv.org/pdf/2405.08829">pdf</a>, <a href="https://arxiv.org/ps/2405.08829">ps</a>, <a href="https://arxiv.org/format/2405.08829">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="High Energy Astrophysical Phenomena">astro-ph.HE</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Plasma Physics">physics.plasm-ph</span> </div> </div> <p class="title is-5 mathjax"> Plasma Effects on Resonant Phenomena </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Pradhan%2C+A">Anil Pradhan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2405.08829v1-abstract-short" style="display: inline;"> The effect of autoionizing resonances in atomic systems and processes is reviewed. Theoretical framework for treating resonances in the coupled channel approximation using the R-matrix method, as well as approximations related to plasma applications are described. The former entails large-scale atomic computations, and the latter is based on a new method for including collisional, Stark, thermal a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.08829v1-abstract-full').style.display = 'inline'; document.getElementById('2405.08829v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.08829v1-abstract-full" style="display: none;"> The effect of autoionizing resonances in atomic systems and processes is reviewed. Theoretical framework for treating resonances in the coupled channel approximation using the R-matrix method, as well as approximations related to plasma applications are described. The former entails large-scale atomic computations, and the latter is based on a new method for including collisional, Stark, thermal and other broadening mechanisms. We focus particularly on the problem of opacities calculations in high-energy-density (HED) plasmas such as stellar interiors and inertial confinement fusion devices. The treatment is generally relevant to radiative and collisional processes as the cross sections become energy-temperature-density dependent. While the computational difficulty increases considerably, the reaction rates are significantly affected. The related issue of the Boltzmann-Saha equation-of-state and its variants in local-thermodynamic-equilibrium (LTE) is also explored as the intermediary between atomic data on the one hand and plasma environments on the other. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.08829v1-abstract-full').style.display = 'none'; document.getElementById('2405.08829v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 13 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">In press, Canadian Journal of Physics, 10 pages, 1 figure. arXiv admin note: substantial text overlap with arXiv:2301.07734</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2404.03510">arXiv:2404.03510</a> <span> [<a href="https://arxiv.org/pdf/2404.03510">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Applied Physics">physics.app-ph</span> </div> </div> <p class="title is-5 mathjax"> Materials for High Temperature Digital Electronics </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Pradhan%2C+D+K">Dhiren K. Pradhan</a>, <a href="/search/physics?searchtype=author&query=Moore%2C+D+C">David C. Moore</a>, <a href="/search/physics?searchtype=author&query=Francis%2C+A+M">A. Matt Francis</a>, <a href="/search/physics?searchtype=author&query=Kupernik%2C+J">Jacob Kupernik</a>, <a href="/search/physics?searchtype=author&query=Kennedy%2C+W+J">W. Joshua Kennedy</a>, <a href="/search/physics?searchtype=author&query=Glavin%2C+N+R">Nicholas R. Glavin</a>, <a href="/search/physics?searchtype=author&query=Olsson%2C+R+H">Roy H. Olsson III</a>, <a href="/search/physics?searchtype=author&query=Jariwala%2C+D">Deep Jariwala</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2404.03510v2-abstract-short" style="display: inline;"> Silicon microelectronics, consisting of complementary metal oxide semiconductor (CMOS) technology, have changed nearly all aspects of human life from communication to transportation, entertainment, and healthcare. Despite the widespread and mainstream use, current silicon-based devices suffer significant reliability issues at temperatures exceeding 125 C. The emergent technological frontiers of sp… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.03510v2-abstract-full').style.display = 'inline'; document.getElementById('2404.03510v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.03510v2-abstract-full" style="display: none;"> Silicon microelectronics, consisting of complementary metal oxide semiconductor (CMOS) technology, have changed nearly all aspects of human life from communication to transportation, entertainment, and healthcare. Despite the widespread and mainstream use, current silicon-based devices suffer significant reliability issues at temperatures exceeding 125 C. The emergent technological frontiers of space exploration, geothermal energy harvesting, nuclear energy, unmanned avionic systems, and autonomous driving will rely on control systems, sensors, and communication devices which operate at temperatures as high as 500 C and beyond. At these extreme temperatures, active (heat exchanger, phase change cooling) or passive (fins and thermal interface materials) cooling strategies add significant mass and complication which is often infeasible. Thus, new material solutions beyond conventional silicon CMOS devices are necessary for high temperature, resilient electronic systems. Accomplishing this will require a united effort to explore development, integration, and ultimately manufacturing of non-silicon-based logic and memory technologies, non-traditional metals for interconnects, and ceramic packaging technology. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.03510v2-abstract-full').style.display = 'none'; document.getElementById('2404.03510v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 4 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">6 Figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2403.12361">arXiv:2403.12361</a> <span> [<a href="https://arxiv.org/pdf/2403.12361">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Other Condensed Matter">cond-mat.other</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Applied Physics">physics.app-ph</span> </div> </div> <p class="title is-5 mathjax"> Multi-State, Ultra-thin, BEOL-Compatible AlScN Ferroelectric Diodes </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Kim%2C+K">Kwan-Ho Kim</a>, <a href="/search/physics?searchtype=author&query=Han%2C+Z">Zirun Han</a>, <a href="/search/physics?searchtype=author&query=Zhang%2C+Y">Yinuo Zhang</a>, <a href="/search/physics?searchtype=author&query=Musavigharavi%2C+P">Pariasadat Musavigharavi</a>, <a href="/search/physics?searchtype=author&query=Zheng%2C+J">Jeffrey Zheng</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+D+K">Dhiren K. Pradhan</a>, <a href="/search/physics?searchtype=author&query=Stach%2C+E+A">Eric A. Stach</a>, <a href="/search/physics?searchtype=author&query=Olsson%2C+R+H">Roy H. Olsson III</a>, <a href="/search/physics?searchtype=author&query=Jariwala%2C+D">Deep Jariwala</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2403.12361v1-abstract-short" style="display: inline;"> The growth in data generation necessitates efficient data processing technologies to address the von Neumann bottleneck in conventional computer architecture. Memory-driven computing, which integrates non-volatile memory (NVM) devices in a 3D stack, is gaining attention, with CMOS back-end-of-line (BEOL) compatible ferroelectric (FE) diodes being ideal due to their two-terminal design and inherent… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.12361v1-abstract-full').style.display = 'inline'; document.getElementById('2403.12361v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2403.12361v1-abstract-full" style="display: none;"> The growth in data generation necessitates efficient data processing technologies to address the von Neumann bottleneck in conventional computer architecture. Memory-driven computing, which integrates non-volatile memory (NVM) devices in a 3D stack, is gaining attention, with CMOS back-end-of-line (BEOL) compatible ferroelectric (FE) diodes being ideal due to their two-terminal design and inherently selector-free nature, facilitating high-density crossbar arrays. Here, we demonstrate BEOL-compatible, high-performance FE-diodes scaled to 5, 10, and 20 nm FE Al0.72Sc0.28N/Al0.64Sc0.36N films. Through interlayer (IL) engineering, we show substantial improvements in the ON/OFF ratios (>166 times) and rectification ratios (>176 times) in these scaled devices. The superlative characteristics also enables 5-bit multi-state operation with a stable retention. We also experimentally and theoretically demonstrate the counterintuitive result that the inclusion of an IL can lead to a decrease in the ferroelectric switching voltage of the device. An in-depth analysis into the device transport mechanisms is performed, and our compact model aligns seamlessly with the experimental results. Our results suggest the possibility of using scaled AlxSc1-xN FE-diodes for high performance, low-power, embedded NVM. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.12361v1-abstract-full').style.display = 'none'; document.getElementById('2403.12361v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 18 March, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2309.12073">arXiv:2309.12073</a> <span> [<a href="https://arxiv.org/pdf/2309.12073">pdf</a>, <a href="https://arxiv.org/ps/2309.12073">ps</a>, <a href="https://arxiv.org/format/2309.12073">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Plasma Physics">physics.plasm-ph</span> </div> </div> <p class="title is-5 mathjax"> Interface of Equation-of-State, Atomic Data and Opacities in the Solar Problem </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">Anil K. Pradhan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2309.12073v1-abstract-short" style="display: inline;"> Convergence of the Rosseland Mean Opacity (RMO) is investigated with respect to the equation-of-state (EOS) and the number of atomic levels of iron ions prevalent at the solar radiative/convection boundary. The "chemical picture" Mihalas-Hummer-Däppen MHD-EOS, and its variant QMHD-EOS, are studied at two representative temperature-density sets at the base of the convection zone (BCZ) and the Sandi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.12073v1-abstract-full').style.display = 'inline'; document.getElementById('2309.12073v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2309.12073v1-abstract-full" style="display: none;"> Convergence of the Rosseland Mean Opacity (RMO) is investigated with respect to the equation-of-state (EOS) and the number of atomic levels of iron ions prevalent at the solar radiative/convection boundary. The "chemical picture" Mihalas-Hummer-Däppen MHD-EOS, and its variant QMHD-EOS, are studied at two representative temperature-density sets at the base of the convection zone (BCZ) and the Sandia Z experiment: $(2 \times 10^6K, \ 10^{23}/cc)$ and $(2.11 \times 10^6K, \ 3.16 \times 10^{22}/cc)$, respectively. It is found that whereas the new atomic datasets from accurate R-matrix calculations for opacities (RMOP) are vastly overcomplete, involving hundreds to over a thousand levels of each of the three Fe ions considered -- FeXVII, FeXVIII and FeXIX -- the EOS constrains contributions to RMOs by relatively fewer levels. The RMOP iron opacity spectrum is quite different from the Opacity Project distorted wave model and shows considerably more plasma broadening effects. This work points to possible improvements needed in the EOS for opacities in high-energy-density (HED) plasma sources. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.12073v1-abstract-full').style.display = 'none'; document.getElementById('2309.12073v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">5 pages, 3 tables, 3 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2309.04555">arXiv:2309.04555</a> <span> [<a href="https://arxiv.org/pdf/2309.04555">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Applied Physics">physics.app-ph</span> </div> </div> <p class="title is-5 mathjax"> Scalable and Stable Ferroelectric Non-Volatile Memory at > 500 $^\circ$C </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Pradhan%2C+D+K">Dhiren K. Pradhan</a>, <a href="/search/physics?searchtype=author&query=Moore%2C+D+C">David C. Moore</a>, <a href="/search/physics?searchtype=author&query=Kim%2C+G">Gwangwoo Kim</a>, <a href="/search/physics?searchtype=author&query=He%2C+Y">Yunfei He</a>, <a href="/search/physics?searchtype=author&query=Musavigharavi%2C+P">Pariasadat Musavigharavi</a>, <a href="/search/physics?searchtype=author&query=Kim%2C+K">Kwan-Ho Kim</a>, <a href="/search/physics?searchtype=author&query=Sharma%2C+N">Nishant Sharma</a>, <a href="/search/physics?searchtype=author&query=Han%2C+Z">Zirun Han</a>, <a href="/search/physics?searchtype=author&query=Du%2C+X">Xingyu Du</a>, <a href="/search/physics?searchtype=author&query=Puli%2C+V+S">Venkata S. Puli</a>, <a href="/search/physics?searchtype=author&query=Stach%2C+E+A">Eric A. Stach</a>, <a href="/search/physics?searchtype=author&query=Kennedy%2C+W+J">W. Joshua Kennedy</a>, <a href="/search/physics?searchtype=author&query=Glavin%2C+N+R">Nicholas R. Glavin</a>, <a href="/search/physics?searchtype=author&query=Olsson%2C+R+H">Roy H. Olsson III</a>, <a href="/search/physics?searchtype=author&query=Jariwala%2C+D">Deep Jariwala</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2309.04555v1-abstract-short" style="display: inline;"> Non-volatile memory (NVM) devices that reliably operate at temperatures above 300 $^\circ$C are currently non-existent and remains a critically unmet challenge in the development of high-temperature (T) resilient electronics, necessary for many emerging, complex computing and sensing in harsh environments. Ferroelectric Al$_x$Sc$_{1-x}$N exhibits strong potential for utilization in NVM devices ope… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.04555v1-abstract-full').style.display = 'inline'; document.getElementById('2309.04555v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2309.04555v1-abstract-full" style="display: none;"> Non-volatile memory (NVM) devices that reliably operate at temperatures above 300 $^\circ$C are currently non-existent and remains a critically unmet challenge in the development of high-temperature (T) resilient electronics, necessary for many emerging, complex computing and sensing in harsh environments. Ferroelectric Al$_x$Sc$_{1-x}$N exhibits strong potential for utilization in NVM devices operating at very high temperatures (> 500 $^\circ$C) given its stable and high remnant polarization (PR) above 100 $μ$C/cm$^2$ with demonstrated ferroelectric transition temperature (TC) > 1000 $^\circ$C. Here, we demonstrate an Al$_{0.68}$Sc$_{0.32}$N ferroelectric diode based NVM device that can reliably operate with clear ferroelectric switching up to 600 $^\circ$C with distinguishable On and Off states. The coercive field (EC) from the Pulsed I-V measurements is found to be -5.84 (EC-) and +5.98 (EC+) (+/- 0.1) MV/cm at room temperature (RT) and found to decrease with increasing temperature up to 600 $^\circ$C. The devices exhibit high remnant polarizations (> 100 $μ$C/cm$^2$) which are stable at high temperatures. At 500 $^\circ$C, our devices show 1 million read cycles and stable On-Off ratio above 1 for > 6 hours. Finally, the operating voltages of our AlScN ferrodiodes are < 15 V at 600 $^\circ$C which is well matched and compatible with Silicon Carbide (SiC) based high temperature logic technology, thereby making our demonstration a major step towards commercialization of NVM integrated high-T computers. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.04555v1-abstract-full').style.display = 'none'; document.getElementById('2309.04555v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">MS and SI</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2308.14882">arXiv:2308.14882</a> <span> [<a href="https://arxiv.org/pdf/2308.14882">pdf</a>, <a href="https://arxiv.org/ps/2308.14882">ps</a>, <a href="https://arxiv.org/format/2308.14882">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Plasma Physics">physics.plasm-ph</span> </div> </div> <p class="title is-5 mathjax"> R-Matrix calculations for opacities: I. Methodology and computations </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">A. K. Pradhan</a>, <a href="/search/physics?searchtype=author&query=Nahar%2C+S+N">S. N. Nahar</a>, <a href="/search/physics?searchtype=author&query=Eissner%2C+W">W. Eissner</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2308.14882v1-abstract-short" style="display: inline;"> An extended version of the R-matrix methodology is presented for calculation of radiative parameters for improved plasma opacities. Contrast and comparisons with existing methods primarily relying on the Distorted Wave (DW) approximation are discussed to verify accuracy and resolve outstanding issues, particularly with reference to the Opacity Project (OP). Among the improvements incorporated are:… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.14882v1-abstract-full').style.display = 'inline'; document.getElementById('2308.14882v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2308.14882v1-abstract-full" style="display: none;"> An extended version of the R-matrix methodology is presented for calculation of radiative parameters for improved plasma opacities. Contrast and comparisons with existing methods primarily relying on the Distorted Wave (DW) approximation are discussed to verify accuracy and resolve outstanding issues, particularly with reference to the Opacity Project (OP). Among the improvements incorporated are: (i) large-scale Breit-Pauli R-matrix (BPRM) calculations for complex atomic systems including fine structure, (ii) convergent close coupling wave function expansions for the (e+ion) system to compute oscillator strengths and photoionization cross sections, (iii) open and closed shell iron ions of interest in astrophysics and experiments, (iv) a treatment for plasma broadening of autoionizing resonances as function of energy-temperature-density dependent cross sections, (v) a "top-up" procedure to compare convergence with R-matrix calculations for highly excited levels, and (vi) spectroscopic identification of resonances and bound \eion levels. The present R-matrix monochromatic opacity spectra are fundamentally different from OP and lead to enhanced Rosseland and Planck mean opacities. An outline of the work reported in other papers in this series and those in progress is presented. Based on the present re-examination of the OP work, it is evident that opacities of heavy elements require revisions in high temperature-density plasma sources. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.14882v1-abstract-full').style.display = 'none'; document.getElementById('2308.14882v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 28 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">16 pages, 2 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2308.14880">arXiv:2308.14880</a> <span> [<a href="https://arxiv.org/pdf/2308.14880">pdf</a>, <a href="https://arxiv.org/ps/2308.14880">ps</a>, <a href="https://arxiv.org/format/2308.14880">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Plasma Physics">physics.plasm-ph</span> </div> </div> <p class="title is-5 mathjax"> R-Matrix calculations for opacities: IV. Convergence, completeness, and comparison of relativistic R-matrix and distorted wave calculations for FeXVII and FeXVIII </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Zhao%2C+L">L. Zhao</a>, <a href="/search/physics?searchtype=author&query=Nahar%2C+S+N">S. N. Nahar</a>, <a href="/search/physics?searchtype=author&query=Eissner%2C+W">W. Eissner</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">A. K. Pradhan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2308.14880v1-abstract-short" style="display: inline;"> To investigate the completeness of coupled channel (CC) Breit-Pauli R-Matrix (BPRM) calculations for opacities, we employ the relativistic distorted wave (RDW) method to complement (``top-up'') and compare the BPRM photoionization cross sections for high-$n\ell$ levels of both FeXVII and FeXVIII. Good agreement is found in background photoionization cross sections using these two methods, which al… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.14880v1-abstract-full').style.display = 'inline'; document.getElementById('2308.14880v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2308.14880v1-abstract-full" style="display: none;"> To investigate the completeness of coupled channel (CC) Breit-Pauli R-Matrix (BPRM) calculations for opacities, we employ the relativistic distorted wave (RDW) method to complement (``top-up'') and compare the BPRM photoionization cross sections for high-$n\ell$ levels of both FeXVII and FeXVIII. Good agreement is found in background photoionization cross sections using these two methods, which also ensures correct matching of bound level cross sections for completeness. In order to top-up the CC-BPRM calculations, bound-bound transitions involving additional bound levels, and a large number of doubly-excited quasi-bound levels corresponding to BPRM autoionizing resonances described in paper RMOPII, are calculated using the RDW method. Photoionization cross sections in the high energy region are also computed and compared up to about 500 $Ry$, and contributions from higher core level excitations than BPRM are considered. The effect of configuration interaction is investigated, which plays a significant role in correctly reproducing some background cross sections. Owing to the fact that the additional RDW levels correspond to high-$n\ell$ bound levels that are negligibly populated according to the Mihalas-Hummer-Däppen equation-of-state (Paper I), the effect on opacities is expected to be small. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.14880v1-abstract-full').style.display = 'none'; document.getElementById('2308.14880v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 28 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">15 pages, 6 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2308.14870">arXiv:2308.14870</a> <span> [<a href="https://arxiv.org/pdf/2308.14870">pdf</a>, <a href="https://arxiv.org/ps/2308.14870">ps</a>, <a href="https://arxiv.org/format/2308.14870">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Plasma Physics">physics.plasm-ph</span> </div> </div> <p class="title is-5 mathjax"> R-matrix calculations for opacities: III. Plasma broadening of autoionizing resonances </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">A. K. Pradhan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2308.14870v1-abstract-short" style="display: inline;"> A general formulation is employed to study and quantitatively ascertain the effect of plasma broadening of {\it intrinsic} autoionizing (AI) resonances in photoionization cross sections. In particular, R-matrix data for iron ions described in the previous paper in the RMOP series (RMOP-II, hereafter RMOP2) are used to demonstrate underlying physical mechanisms due to electron collisions, ion micro… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.14870v1-abstract-full').style.display = 'inline'; document.getElementById('2308.14870v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2308.14870v1-abstract-full" style="display: none;"> A general formulation is employed to study and quantitatively ascertain the effect of plasma broadening of {\it intrinsic} autoionizing (AI) resonances in photoionization cross sections. In particular, R-matrix data for iron ions described in the previous paper in the RMOP series (RMOP-II, hereafter RMOP2) are used to demonstrate underlying physical mechanisms due to electron collisions, ion microfields (Stark), thermal Doppler effects, core excitations, and free-free transitions. Breit-Pauli R-matrix (BPRM) cross section for the large number of bound levels of Fe ions are considered, 454 levels of Fe~XVII, 1,184 levels of Fe~XVIII and 508 levels of Fe~XIX. Following a description of theoretical and computational methods, a sample of results is presented to show significant broadening and shifting of AI resonances due to {\it Extrinsic} plasma broadening as a function of temperature and density. Redistribution of AI resonance strengths broadly preserves their integrated strengths as well as the naturally {\it intrinsic} asymmetric shapes of resonance complexes which are broadened, smeared and flattened, eventually dissolving into the bound-free continua. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.14870v1-abstract-full').style.display = 'none'; document.getElementById('2308.14870v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 28 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">20 pages, 5 figures. arXiv admin note: substantial text overlap with arXiv:2301.07734</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2308.14854">arXiv:2308.14854</a> <span> [<a href="https://arxiv.org/pdf/2308.14854">pdf</a>, <a href="https://arxiv.org/format/2308.14854">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Plasma Physics">physics.plasm-ph</span> </div> </div> <p class="title is-5 mathjax"> R-Matrix calculations for opacities.II. Photoionization and oscillator strengths of iron ions FeXVII, FeXVIII and FeXIX </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Nahar%2C+S+N">S. N. Nahar</a>, <a href="/search/physics?searchtype=author&query=Zhao%2C+L">L. Zhao</a>, <a href="/search/physics?searchtype=author&query=Eissner%2C+W">W. Eissner</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">A. K. Pradhan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2308.14854v1-abstract-short" style="display: inline;"> Iron is the dominant heavy element that plays an important role in radiation transport in stellar interiors. Owing to its abundance and large number of bound levels and transitions, iron ions determine the opacity more than any other astrophysically abundant element. A few iron ions constitute the abundance and opacity of iron at the base of the convection zone (BCZ) at the boundary between the so… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.14854v1-abstract-full').style.display = 'inline'; document.getElementById('2308.14854v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2308.14854v1-abstract-full" style="display: none;"> Iron is the dominant heavy element that plays an important role in radiation transport in stellar interiors. Owing to its abundance and large number of bound levels and transitions, iron ions determine the opacity more than any other astrophysically abundant element. A few iron ions constitute the abundance and opacity of iron at the base of the convection zone (BCZ) at the boundary between the solar convection and radiative zones, and are the focus of the present study. Together, FeXVII, FeXVIII and FeXIX contribute 85\% of iron ion fractions 20\%, 39\% and 26\% respectively, at the BCZ physical conditions. We report heretofore the most extensive R-matrix atomic calculations for these ions for bound-bound and bound-free transitions, the two main processes of radiation absorption. We consider wavefunction expansions with 218 target or core ion fine structure levels of FeXVIII for FeXVII, 276 levels of FeXIX for FeXVIII, in the Breit-Pauli R-matrix (BPRM) approximation, and 180 LS terms (equivalent to 415 fine structure levels) of FeXX for FeXIX calculations. These large target expansions which includes core ion excitations to n=2,3,4 complexes enable accuracy and convergence of photoionization cross sections, as well as inclusion of high lying resonances. Photoionization cross sections have obtained for all bound fine structure levels of FeXVII and FeXVIII, and for 900 bound LS states of FeXIX. Selected results demonstrating prominent characteristic features of photoionization are presented, particularly the strong Seaton PEC (photoexcitation-of-core) resonances formed via high-lying core excitations with $Δn=1$ that significantly impact bound-free opacity. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.14854v1-abstract-full').style.display = 'none'; document.getElementById('2308.14854v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 28 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">22 pages, 10 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2303.03444">arXiv:2303.03444</a> <span> [<a href="https://arxiv.org/pdf/2303.03444">pdf</a>, <a href="https://arxiv.org/ps/2303.03444">ps</a>, <a href="https://arxiv.org/format/2303.03444">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Plasma Physics">physics.plasm-ph</span> </div> </div> <p class="title is-5 mathjax"> Photoionization and Opacity </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Pradhan%2C+A">Anil Pradhan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2303.03444v1-abstract-short" style="display: inline;"> Opacity determines radiation transport through material media. In a plasma source the primary contributors to atomic opacity are bound-bound line transitions and bound-free photoionization into the continuum. We review the theoretical methodology for state-of-the-art photoionization calculations based on the R-matrix method as employed in the Opacity Project, the Iron Project, and solution of the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.03444v1-abstract-full').style.display = 'inline'; document.getElementById('2303.03444v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.03444v1-abstract-full" style="display: none;"> Opacity determines radiation transport through material media. In a plasma source the primary contributors to atomic opacity are bound-bound line transitions and bound-free photoionization into the continuum. We review the theoretical methodology for state-of-the-art photoionization calculations based on the R-matrix method as employed in the Opacity Project, the Iron Project, and solution of the heretofore unsolved problem of plasma broadening of autoionizing resonances due to electron impact, Stark (electric microfields), Doppler (thermal), and core-excitations. R-matrix opacity calculations entail huge amount of atomic data and calculations of unprecedented complexity. It is shown that in high-energy-density (HED) plasmas Photoionization cross sections become 3-D energy-temperature-density dependent owing to considerable attenuation of autoionizing resonance profiles. Hence, differential oscillator strengths and monochromatic opacities are redistributed in energy. Consequently, Rosseland and Planck mean opacities are affected significantly. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.03444v1-abstract-full').style.display = 'none'; document.getElementById('2303.03444v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 6 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">14 pages, 3 fifgures, appeared in Atoms, 11, 52 (2023)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2301.07734">arXiv:2301.07734</a> <span> [<a href="https://arxiv.org/pdf/2301.07734">pdf</a>, <a href="https://arxiv.org/ps/2301.07734">ps</a>, <a href="https://arxiv.org/format/2301.07734">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Plasma Physics">physics.plasm-ph</span> </div> </div> <p class="title is-5 mathjax"> Plasma broadening of autoionizing resonances </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Pradhan%2C+A">Anil Pradhan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2301.07734v1-abstract-short" style="display: inline;"> A general formulation is developed to demonstrate that atomic autoionizing (AI) resonances are broadened and shifted significantly due to plasma effects across bound-free continua. The theoretical and computational method presented accounts for broadening mechanisms: electron collisional, ion microfields (Stark), thermal Doppler, core excitations, and free-free transitions. {\it Extrinsic} plasma… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2301.07734v1-abstract-full').style.display = 'inline'; document.getElementById('2301.07734v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2301.07734v1-abstract-full" style="display: none;"> A general formulation is developed to demonstrate that atomic autoionizing (AI) resonances are broadened and shifted significantly due to plasma effects across bound-free continua. The theoretical and computational method presented accounts for broadening mechanisms: electron collisional, ion microfields (Stark), thermal Doppler, core excitations, and free-free transitions. {\it Extrinsic} plasma broadening redistributes and shifts AI resonance strengths while broadly preserving naturally {\it intrinsic} asymmetries of resonance profiles. Integrated oscillator strengths are conserved as resonance structures dissolve into continua with increasing electron density. As exemplar, the plasma attenuation of photoionization cross sections computed using the R-matrix method is studied in neon-like Fe~XVII in a critical range $N_e = 10^{21-24}$cc along isotherms $T = 1-2 \times 10^6$K, and its impact on Rosseland Mean opacities. The energy-temperature-density dependent cross sections would elicit and introduce physical features in resonant processes in photoionization, \eion excitation and recombination. The method should be generally applicable to atomic species in high-energy-density (HED) sources such as fusion plasmas and stellar interiors. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2301.07734v1-abstract-full').style.display = 'none'; document.getElementById('2301.07734v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 18 January, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">5 pages, 3 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2206.12564">arXiv:2206.12564</a> <span> [<a href="https://arxiv.org/pdf/2206.12564">pdf</a>, <a href="https://arxiv.org/ps/2206.12564">ps</a>, <a href="https://arxiv.org/format/2206.12564">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1002/adom.202200791">10.1002/adom.202200791 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Nonlinear coherent light-matter interaction in 2D MoSe$_2$ nanoflakes for all-optical switching and logic applications </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Kalimuddin%2C+S">Sk Kalimuddin</a>, <a href="/search/physics?searchtype=author&query=Das%2C+B">Biswajit Das</a>, <a href="/search/physics?searchtype=author&query=Chakraborty%2C+N">Nabamita Chakraborty</a>, <a href="/search/physics?searchtype=author&query=Samanta%2C+M">Madhupriya Samanta</a>, <a href="/search/physics?searchtype=author&query=Bera%2C+S">Satyabrata Bera</a>, <a href="/search/physics?searchtype=author&query=Bera%2C+A">Arnab Bera</a>, <a href="/search/physics?searchtype=author&query=Roy%2C+D+S">Deep Singha Roy</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+S+K">Suman Kalyan Pradhan</a>, <a href="/search/physics?searchtype=author&query=Chattopadhyay%2C+K+K">Kalyan K. Chattopadhyay</a>, <a href="/search/physics?searchtype=author&query=Mondal%2C+M">Mintu Mondal</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2206.12564v1-abstract-short" style="display: inline;"> We report a strong nonlinear optical response of 2D MoSe$_2$ nanoflakes (NFs) through spatial self-phase modulation (SSPM) and cross-phase modulation (XPM) induced by nonlocal coherent light-matter interactions. The coherent interaction of light and MoSe$_2$ NFs creates the SSPM of laser beams, forming concentric diffraction rings. The nonlinear refractive index ($n_2$) and the third-order broadba… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.12564v1-abstract-full').style.display = 'inline'; document.getElementById('2206.12564v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2206.12564v1-abstract-full" style="display: none;"> We report a strong nonlinear optical response of 2D MoSe$_2$ nanoflakes (NFs) through spatial self-phase modulation (SSPM) and cross-phase modulation (XPM) induced by nonlocal coherent light-matter interactions. The coherent interaction of light and MoSe$_2$ NFs creates the SSPM of laser beams, forming concentric diffraction rings. The nonlinear refractive index ($n_2$) and the third-order broadband nonlinear optical susceptibility ($χ^{(3)}$) of MoSe$_2$ NFs are determined from the self diffraction pattern at different exciting wavelengths of 405, 532, and 671 nm with varying the laser intensity. The evolution and deformation of diffraction ring patterns are observed and analyzed by the `wind-chime' model and thermal effect. By taking advantage of the reverse saturated absorption of 2D SnS$_2$ NFs compared to MoSe$_2$, an all-optical diode has been designed with MoSe$_2$/SnS$_2$ hybrid structure to demonstrate the nonreciprocal light propagation. Also a few other optical devices based on MoSe$_2$ and other semiconducting materials such as Bi$_2$Se$_3$, CuPc, and graphene have been investigated. The all-optical logic gates and all-optical information conversion have been demonstrated through the XPM technique using two laser beams. The proposed optical scheme based on MoSe$_2$ NFs has been demonstrated as a potential candidate for all-optical nonlinear photonic devices such as all-optical diodes and all-optical switches. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.12564v1-abstract-full').style.display = 'none'; document.getElementById('2206.12564v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 June, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">20 pages, 6 figures, accepted in advanced optical materials</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2201.11399">arXiv:2201.11399</a> <span> [<a href="https://arxiv.org/pdf/2201.11399">pdf</a>, <a href="https://arxiv.org/format/2201.11399">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Applied Physics">physics.app-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1364/OL.456109">10.1364/OL.456109 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Experimental observation of Berreman modes in uniaxial anisotropic nanoporous alumina film on aluminium substrate </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Pratap%2C+D">Dheeraj Pratap</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+J+K">Jitendra Kumar Pradhan</a>, <a href="/search/physics?searchtype=author&query=Ramakrishna%2C+S+A">Subramanium Anantha Ramakrishna</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2201.11399v1-abstract-short" style="display: inline;"> In this article, we demonstrate experimentally and verified numerically the excitation of Berreman modes that propagate in a dielectric film of uniaxial anisotropic nanoporous alumina grown on an aluminium substrate. It is an air-dielectric-metal asymmetric polaritonic system with a real part of the effective permittivity having a value near zero. The modes are excited at a wavelength lower than t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2201.11399v1-abstract-full').style.display = 'inline'; document.getElementById('2201.11399v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2201.11399v1-abstract-full" style="display: none;"> In this article, we demonstrate experimentally and verified numerically the excitation of Berreman modes that propagate in a dielectric film of uniaxial anisotropic nanoporous alumina grown on an aluminium substrate. It is an air-dielectric-metal asymmetric polaritonic system with a real part of the effective permittivity having a value near zero. The modes are excited at a wavelength lower than the epsilon near zero wavelength region. Minimum reflection is observed for the mid-infrared p-polarized light, while maximum reflection is observed for the s-polarized light. The experimental results are numerically reproduced for both p- and s-polarized light and confirm the Berreman modes excitation in the system. At the exciting wavelength, the field is confined in the dielectric region near the air-dielectric interface. The reported system is straightforward and could be easily fabricated over a large scale and is helpful in a variety of mid-infrared applications such as thermal management systems, sensors, passive radiative cooling devices, non-linear applications, and terahertz frequency generation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2201.11399v1-abstract-full').style.display = 'none'; document.getElementById('2201.11399v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 27 January, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">14 pages, 6 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2004.11614">arXiv:2004.11614</a> <span> [<a href="https://arxiv.org/pdf/2004.11614">pdf</a>, <a href="https://arxiv.org/ps/2004.11614">ps</a>, <a href="https://arxiv.org/format/2004.11614">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Fluid Dynamics">physics.flu-dyn</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Applied Physics">physics.app-ph</span> </div> </div> <p class="title is-5 mathjax"> Induced flow inside a droplet by static electrical charge </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Pradhan%2C+T+K">Tapan Kumar Pradhan</a>, <a href="/search/physics?searchtype=author&query=Banuprasad%2C+T+N">T. N. Banuprasad</a>, <a href="/search/physics?searchtype=author&query=Nandagopal%2C+M+S+G">M. S. Giri Nandagopal</a>, <a href="/search/physics?searchtype=author&query=Chakraborty%2C+S">Suman Chakraborty</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2004.11614v1-abstract-short" style="display: inline;"> Introducing controlled fluid motion inside a droplet turns out to be of outstanding scientific importance. In this work, we suggest a new method of flow manipulation inside a sessile droplet by simply deploying a static charge produced by triboelectric effect. This is physically actuated by charge transfer between the two lateral electrodes within which the droplet is entrained, triggering a stron… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2004.11614v1-abstract-full').style.display = 'inline'; document.getElementById('2004.11614v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2004.11614v1-abstract-full" style="display: none;"> Introducing controlled fluid motion inside a droplet turns out to be of outstanding scientific importance. In this work, we suggest a new method of flow manipulation inside a sessile droplet by simply deploying a static charge produced by triboelectric effect. This is physically actuated by charge transfer between the two lateral electrodes within which the droplet is entrained, triggering a strong ionized air current. The flow inside the droplet is generated due to the shear exerted at the liquid-air interface by the charged induced ionized air flow around the droplet, a paradigm that has hitherto remained unexplored. The strength of the fluid flow can be controlled by adjusting the supplied charge. Such unique controllability without sacrificing the physical simplicity opens up new possibilities of flow manipulation in a multitude of applications in droplet based microfluidics. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2004.11614v1-abstract-full').style.display = 'none'; document.getElementById('2004.11614v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 24 April, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2020. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2004.01730">arXiv:2004.01730</a> <span> [<a href="https://arxiv.org/pdf/2004.01730">pdf</a>, <a href="https://arxiv.org/ps/2004.01730">ps</a>, <a href="https://arxiv.org/format/2004.01730">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Fluid Dynamics">physics.flu-dyn</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Soft Condensed Matter">cond-mat.soft</span> </div> </div> <p class="title is-5 mathjax"> Unexpectedly absence of Marangoni convection in an evaporating water meniscus </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Pradhan%2C+T+K">Tapan Kumar Pradhan</a>, <a href="/search/physics?searchtype=author&query=Panigrahi%2C+P+K">Pradipta Kumar Panigrahi</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2004.01730v2-abstract-short" style="display: inline;"> It is usually expected that surface tension driven flow dominates at small scales. Evaporation from the meniscus of ethanol/methanol confined in a capillary induces Marangoni convection at the meniscus which has been investigated by previous researchers. However, Marangoni convection is unexpectedly absent at an evaporating water meniscus confined inside a small micro-channel which is reported in… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2004.01730v2-abstract-full').style.display = 'inline'; document.getElementById('2004.01730v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2004.01730v2-abstract-full" style="display: none;"> It is usually expected that surface tension driven flow dominates at small scales. Evaporation from the meniscus of ethanol/methanol confined in a capillary induces Marangoni convection at the meniscus which has been investigated by previous researchers. However, Marangoni convection is unexpectedly absent at an evaporating water meniscus confined inside a small micro-channel which is reported in this work. The velocity near the water meniscus is studied using confocal micro-PIV. The water meniscus is formed at the end of a micro-channel filled with water keeping the meniscus exposed to atmosphere. The flow near the evaporating water meniscus is caused by combined effect of capillary flow to replenish water loss at the meniscus and buoyancy flow caused by evaporation induced temperature gradient. Unidirectional capillary flow dominates for small capillary size where as circulating buoyancy convection dominates in larger capillary size. The reported unexpected behavior of flow at the evaporating water meniscus will be helpful to understand the inter-facial phenomena in future studies. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2004.01730v2-abstract-full').style.display = 'none'; document.getElementById('2004.01730v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 22 April, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 3 April, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2020. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2003.09263">arXiv:2003.09263</a> <span> [<a href="https://arxiv.org/pdf/2003.09263">pdf</a>, <a href="https://arxiv.org/ps/2003.09263">ps</a>, <a href="https://arxiv.org/format/2003.09263">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Soft Condensed Matter">cond-mat.soft</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Fluid Dynamics">physics.flu-dyn</span> </div> </div> <p class="title is-5 mathjax"> Suppressing convection strength using confinement during protein crystallization </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Pradhan%2C+T+K">Tapan Kumar Pradhan</a>, <a href="/search/physics?searchtype=author&query=Panigrahi%2C+P+K">Pradipta Kumar Panigrahi</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2003.09263v1-abstract-short" style="display: inline;"> Fluid convection during protein crystallization plays a significant role in determining crystal growth rate and crystal quality. Crystals grown in reduced flow strength gives better quality crystal. Hence, tuning the flow strength is very essential in the crystal growth process. In this work, we have demonstrated a new method to suppress the flow strength using confinement effect during vapor diff… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2003.09263v1-abstract-full').style.display = 'inline'; document.getElementById('2003.09263v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2003.09263v1-abstract-full" style="display: none;"> Fluid convection during protein crystallization plays a significant role in determining crystal growth rate and crystal quality. Crystals grown in reduced flow strength gives better quality crystal. Hence, tuning the flow strength is very essential in the crystal growth process. In this work, we have demonstrated a new method to suppress the flow strength using confinement effect during vapor diffusion method of protein crystallization where the crystal is grown inside an evaporating droplet. Flow study is carried out at four different confinement conditions to study the effect of confinement. Flow inside the droplet is caused by evaporation induced natural convection which is measured by micro-PIV method. Also concentration gradient generated around the growing crystal also induces buoyancy driven flow around the protein crystal during the crystal growth phase. The evaporation rate from the droplet and the flow strength inside the droplet get suppressed by increasing confinement. Hence, the flow strength can be tuned by adjusting the confinement which is a very simple method to tune the flow strength. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2003.09263v1-abstract-full').style.display = 'none'; document.getElementById('2003.09263v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 March, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2020. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2003.09013">arXiv:2003.09013</a> <span> [<a href="https://arxiv.org/pdf/2003.09013">pdf</a>, <a href="https://arxiv.org/ps/2003.09013">ps</a>, <a href="https://arxiv.org/format/2003.09013">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Fluid Dynamics">physics.flu-dyn</span> </div> </div> <p class="title is-5 mathjax"> Condensation induced internal convection of two neighboring droplets </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Pradhan%2C+T+K">Tapan Kumar Pradhan</a>, <a href="/search/physics?searchtype=author&query=Panigrahi%2C+P+K">Pradipta Kumar Panigrahi</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2003.09013v2-abstract-short" style="display: inline;"> The present work investigates the internal flow structure of two condensing droplets of aqueous solution during interaction. The velocity of fluid inside the droplets was investigated by confocal micro-PIV technique. Condensation on the droplets was carried out inside a closed chamber by creating a difference in vapor pressure between the droplet interface and a reservoir fluid surrounding the dro… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2003.09013v2-abstract-full').style.display = 'inline'; document.getElementById('2003.09013v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2003.09013v2-abstract-full" style="display: none;"> The present work investigates the internal flow structure of two condensing droplets of aqueous solution during interaction. The velocity of fluid inside the droplets was investigated by confocal micro-PIV technique. Condensation on the droplets was carried out inside a closed chamber by creating a difference in vapor pressure between the droplet interface and a reservoir fluid surrounding the droplet in the room temperature without any cooling. Condensation on the droplet leads to spatial variation of solute concentration inside the droplet causing buoyancy driven Rayleigh convection. Fluid flow pattern inside a single condensing droplet is symmetric in nature where as the fluid flow pattern for two interacting droplets is asymmetric in nature. The neighboring droplet influences the internal convection through vapor mediated interaction between the two condensing droplets. Here, the condensing droplet senses the neighboring droplet from a distance without any physical contact. The asymmetric nature of the flow pattern is attributed to the modification in the distribution of condensation flux of the droplet in the presence of the neighboring droplet. The flow pattern observed for interacting droplets during condensation is opposite to that of evaporating droplets. The effect of the neighboring droplet on the internal convection of the condensing droplet reduces with increase in separation distance between the droplets. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2003.09013v2-abstract-full').style.display = 'none'; document.getElementById('2003.09013v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 24 July, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 19 March, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2020. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2002.11540">arXiv:2002.11540</a> <span> [<a href="https://arxiv.org/pdf/2002.11540">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Applied Physics">physics.app-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1088/1361-6528/abb42c">10.1088/1361-6528/abb42c <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Thermal conductivity of free-standing silicon nanowire using Raman spectroscopy </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Sahoo%2C+S">Sandhyarani Sahoo</a>, <a href="/search/physics?searchtype=author&query=Mallik%2C+S+K">Sameer Kumar Mallik</a>, <a href="/search/physics?searchtype=author&query=Sahu%2C+M+C">Mousam Charan Sahu</a>, <a href="/search/physics?searchtype=author&query=Joseph%2C+A">Anjana Joseph</a>, <a href="/search/physics?searchtype=author&query=Rout%2C+B">Bibhudutta Rout</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+G+K">Gopal K. Pradhan</a>, <a href="/search/physics?searchtype=author&query=Sahoo%2C+S">Satyaprakash Sahoo</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2002.11540v1-abstract-short" style="display: inline;"> Low dimensional systems, nanowires, in particular, have exhibited excellent optical and electronic properties. Understanding the thermal properties in semiconductor nanowires is very important for their applications in their electronic devices. In the present study, the thermal conductivity of a freestanding silicon nanowire (NW) is estimated employing the Raman spectroscopy. The advantage of this… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2002.11540v1-abstract-full').style.display = 'inline'; document.getElementById('2002.11540v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2002.11540v1-abstract-full" style="display: none;"> Low dimensional systems, nanowires, in particular, have exhibited excellent optical and electronic properties. Understanding the thermal properties in semiconductor nanowires is very important for their applications in their electronic devices. In the present study, the thermal conductivity of a freestanding silicon nanowire (NW) is estimated employing the Raman spectroscopy. The advantage of this technique is that the light source (laser) can be used both as heating and excitation source. The variations of the first-order Raman peak position of the freestanding silicon NW with respect to temperature and laser power are carried out. A critical analysis of effective laser power absorbed by exposed silicon NW, the detailed Raman study along with the concept of longitudinal heat distribution in silicon NW, the thermal conductivity of the freestanding silicon NW of 112 nm diameter is estimated to be ~53 W/m.K. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2002.11540v1-abstract-full').style.display = 'none'; document.getElementById('2002.11540v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 26 February, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2020. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2001.04291">arXiv:2001.04291</a> <span> [<a href="https://arxiv.org/pdf/2001.04291">pdf</a>, <a href="https://arxiv.org/format/2001.04291">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Applied Physics">physics.app-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1109/LSENS.2020.2982469">10.1109/LSENS.2020.2982469 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Low cost passive pH sensor fabricated on scotch tape </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Majumder%2C+A">Ayan Majumder</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+S+K">Subrat Kumar Pradhan</a>, <a href="/search/physics?searchtype=author&query=Saha%2C+K">Kasturi Saha</a>, <a href="/search/physics?searchtype=author&query=Tallur%2C+S">Siddharth Tallur</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2001.04291v1-abstract-short" style="display: inline;"> We report the fabrication and characterization results of a simple and low-cost pH sensor fabricated using a graphite pencil to define a working electrode and silver paste to define a reference electrode on scotch tape. The sensor operation is based on potentiometric measurement and thereby insensitive to fabrication variations in shape of the electrode unlike amperometric and chemiresistive measu… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.04291v1-abstract-full').style.display = 'inline'; document.getElementById('2001.04291v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2001.04291v1-abstract-full" style="display: none;"> We report the fabrication and characterization results of a simple and low-cost pH sensor fabricated using a graphite pencil to define a working electrode and silver paste to define a reference electrode on scotch tape. The sensor operation is based on potentiometric measurement and thereby insensitive to fabrication variations in shape of the electrode unlike amperometric and chemiresistive measurement techniques. The substrate of the disposable sensor is prepared by pasting scotch tape atop a piece of chart paper, and two types of sensors fabricated with 6B and 2B graphite pencils are tested with three solutions with different pH values. The sensor functions as a passive sensing tag without requiring any external power or stimulus, and the measured sensitivities of the pH sensors fabricated using 2B and 6B pencil carbon electrodes (PCEs) are $-4.54mV/pH$ and $-4.09mV/pH$ respectively. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.04291v1-abstract-full').style.display = 'none'; document.getElementById('2001.04291v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 13 January, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> EEE Sensors Letters, vol. 4, no. 4, pp. 1-4, April 2020, Art no. 2000204 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1902.04377">arXiv:1902.04377</a> <span> [<a href="https://arxiv.org/pdf/1902.04377">pdf</a>, <a href="https://arxiv.org/format/1902.04377">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Applied Physics">physics.app-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> </div> </div> <p class="title is-5 mathjax"> Designing multi-level resistance states for multi-bit storage using half doped manganites </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Banik%2C+S">Sanjib Banik</a>, <a href="/search/physics?searchtype=author&query=Das%2C+K">Kalipada Das</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+K">Kalpataru Pradhan</a>, <a href="/search/physics?searchtype=author&query=Das%2C+I">I. Das</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1902.04377v1-abstract-short" style="display: inline;"> Designing nonvolatile multi-level resistive devices is the necessity of time to go beyond traditional one-bit storage systems, thus enhancing the storage density. Here, we explore the electronic phase competition scenario to design multi-level resistance states using a half doped CE-type charge ordered insulating bulk manganite, $Sm_{0.5}Ca_{0.25}Sr_{0.25}MnO_3$ (SCSMO). By introducing electronic… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1902.04377v1-abstract-full').style.display = 'inline'; document.getElementById('1902.04377v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1902.04377v1-abstract-full" style="display: none;"> Designing nonvolatile multi-level resistive devices is the necessity of time to go beyond traditional one-bit storage systems, thus enhancing the storage density. Here, we explore the electronic phase competition scenario to design multi-level resistance states using a half doped CE-type charge ordered insulating bulk manganite, $Sm_{0.5}Ca_{0.25}Sr_{0.25}MnO_3$ (SCSMO). By introducing electronic phase coexistence in a controllable manner in SCSMO, we show that the system can be stabilized into several metastable states, against thermal cycling, up to 62 K. As a result the magnetization (and the resistivity) remains unaltered during the thermal cycling. Monte Carlo calculations using two-band double exchange model, including super-exchange, electron-phonon coupling, and quenched disorder, show that the system freezes into a phase coexistence metastable state during the thermal cycling due to the chemical disorder in SCSMO. Using the obtained insights we outline a pathway by utilizing four reversible metastable resistance states to design a prototype multi-bit memory device. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1902.04377v1-abstract-full').style.display = 'none'; document.getElementById('1902.04377v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 12 February, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">5 figures, 5 supplementary figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1801.02188">arXiv:1801.02188</a> <span> [<a href="https://arxiv.org/pdf/1801.02188">pdf</a>, <a href="https://arxiv.org/ps/1801.02188">ps</a>, <a href="https://arxiv.org/format/1801.02188">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic and Molecular Clusters">physics.atm-clus</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> </div> <p class="title is-5 mathjax"> Converged Close-Coupling R-Matrix calculations of Photoionization of Fe XVII in Astrophysical Plasmas: from Convergence to Completeness </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Zhao%2C+L">Lianshui Zhao</a>, <a href="/search/physics?searchtype=author&query=Eissner%2C+W">Werner Eissner</a>, <a href="/search/physics?searchtype=author&query=Nahar%2C+S+N">Sultana N. Nahar</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">Anil K. Pradhan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1801.02188v1-abstract-short" style="display: inline;"> Extensive resonance structures are manifest in R-Matrix (RM) calculations. However, there exist a large number of highly excited electronic configurations that may contribute to background non-resonant bound-free opacity in high-temperature plasmas. Since RM calculations are very complex, and not essential for background contributions, the Relativistic Distorted Wave (RDW) method is utilized to co… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1801.02188v1-abstract-full').style.display = 'inline'; document.getElementById('1801.02188v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1801.02188v1-abstract-full" style="display: none;"> Extensive resonance structures are manifest in R-Matrix (RM) calculations. However, there exist a large number of highly excited electronic configurations that may contribute to background non-resonant bound-free opacity in high-temperature plasmas. Since RM calculations are very complex, and not essential for background contributions, the Relativistic Distorted Wave (RDW) method is utilized to complement ("top-up") photoionization cross sections of Fe XVII obtained using Close-Coupling Breit-Pauli R-Matrix (CC-BPRM) method. There is good agreement between RDW and BPRM for background cross sections where resonances are not present, and individual fine structure levels can be correctly matched spectroscopically, though resonances are neglected in the RDW. To ensure completeness, a high energy range up to 500 Ry above the ionization threshold for each level is considered. Interestingly, the hydrogenic Kramer's approximation also shows the same energy behavior as the RDW. Grouping separately, the BPRM configurations consist of 454 bound levels with resonances corresponding to configurations $1s^22s^22p^4nln'l'$ (n $\leq$ 3, n' $\leq$ 10); including RDW configurations there are 51,558 levels in total. The topup contribution results in $\sim$20\% increment, in addition to the 35\% enhancement from BPRM calculations over the Opacity Project value for the Rosseland Mean Opacity at the Z-temperature of 2.11 $\times 10^6$K (Pradhan and Nahar 2017). <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1801.02188v1-abstract-full').style.display = 'none'; document.getElementById('1801.02188v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 January, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2018. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">5 pages, 2 figures, Proc. Workshop on Astrophysical Opacities 2017, PASP</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1801.02085">arXiv:1801.02085</a> <span> [<a href="https://arxiv.org/pdf/1801.02085">pdf</a>, <a href="https://arxiv.org/ps/1801.02085">ps</a>, <a href="https://arxiv.org/format/1801.02085">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> </div> <p class="title is-5 mathjax"> Recalculation of Astrophysical Opacities: Overview, Methodology and Atomic Calculations </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">Anil K. Pradhan</a>, <a href="/search/physics?searchtype=author&query=Nahar%2C+S+N">Sultana N. Nahar</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1801.02085v1-abstract-short" style="display: inline;"> A review of a renewed effort to recalculate astrophysical opacities using the R-Matrix method is presented. The computational methods and new extensions are described. Resulting enhancements found in test calculations under stellar interior conditions compared to the Opacity Project could potentially lead to the resolution of the solar abundances problem, as well as discrepancies between recent ex… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1801.02085v1-abstract-full').style.display = 'inline'; document.getElementById('1801.02085v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1801.02085v1-abstract-full" style="display: none;"> A review of a renewed effort to recalculate astrophysical opacities using the R-Matrix method is presented. The computational methods and new extensions are described. Resulting enhancements found in test calculations under stellar interior conditions compared to the Opacity Project could potentially lead to the resolution of the solar abundances problem, as well as discrepancies between recent experimental measurements at the Sandia Z-pinch inertial confinement fusion device and theoretical opacity models. Outstanding issues also discussed are: (i) accuracy, convergence, and completeness of atomic calculations, (ii) improvements in the Equation-of-State of high-temperature-density plasmas, and (iii) redistribution of resonant oscillator strength in the bound-free continuum, and (iv) plasma broadening of auotionizing resonances. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1801.02085v1-abstract-full').style.display = 'none'; document.getElementById('1801.02085v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 6 January, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2018. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">10 pages, 4 figures, Review, Proc. Workshop on Astrophysical Opacities 2017, PASP</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1304.0799">arXiv:1304.0799</a> <span> [<a href="https://arxiv.org/pdf/1304.0799">pdf</a>, <a href="https://arxiv.org/ps/1304.0799">ps</a>, <a href="https://arxiv.org/format/1304.0799">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stt1398">10.1093/mnras/stt1398 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Fine structure collision strengths and line ratios for [Ne V] in infrared and optical sources </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Dance%2C+M">Michael Dance</a>, <a href="/search/physics?searchtype=author&query=Palay%2C+E">Ethan Palay</a>, <a href="/search/physics?searchtype=author&query=Nahar%2C+S+N">Sultana N. Nahar</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">Anil K. Pradhan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1304.0799v1-abstract-short" style="display: inline;"> Improved collisions strengths for the mid-infrared and optical transitions in Ne V are presented. Breit-Pauli R-Matrix calculations for electron impact excitation are carried out with fully resolved near-threshold resonances at very low energies. In particular, the fine structure lines at 14 micron and 24 micron due to transitions among the ground state levels 1s^22s^22p^3 (^3P_{0,1,2}), and the o… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1304.0799v1-abstract-full').style.display = 'inline'; document.getElementById('1304.0799v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1304.0799v1-abstract-full" style="display: none;"> Improved collisions strengths for the mid-infrared and optical transitions in Ne V are presented. Breit-Pauli R-Matrix calculations for electron impact excitation are carried out with fully resolved near-threshold resonances at very low energies. In particular, the fine structure lines at 14 micron and 24 micron due to transitions among the ground state levels 1s^22s^22p^3 (^3P_{0,1,2}), and the optical/near-UV lines at 2973, 3346 and 3426 Angstrom transitions among the ^3P_{0,1,2}, ^1D_2, ^1S_0 levels are described. Maxwellian averaged collision strengths are tabulated for all forbidden transistion within the ground configuration. Significant differences are found in the low temperature range Te < 10000 K for both the FIR and the opitcal transitions compared to previous results. An analysis of the 14/24 line ratio in low-energy-density (LED) plasma conditions reveals considerable variation; the effective rate coefficient may be dominated by the very low-energy behaviour rather than the maxwellian averaged collision strengths. Computed values suggest a possible solution to the anomalous mid-IR ratios found to be lower than theoretical limits observed from planetary nebulae and Seyfert galaxies. While such LED conditions may be present in infrared sources, they might be inconsistent with photoionization equilibrium models. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1304.0799v1-abstract-full').style.display = 'none'; document.getElementById('1304.0799v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 April, 2013; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2013. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">6 pages, 7 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1303.5634">arXiv:1303.5634</a> <span> [<a href="https://arxiv.org/pdf/1303.5634">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="General Physics">physics.gen-ph</span> </div> </div> <p class="title is-5 mathjax"> Observed Spacetime Dimensionality from Fundamental Principles </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Pradhan%2C+R+K">Rajat K. Pradhan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1303.5634v1-abstract-short" style="display: inline;"> It is shown by very simple arguments that the observed 3+1 dimensionality of spacetime may be understood on the basis of four fundamental principles of physics namely, Causality, General Covariance, Gauge Invariance and Renormalizability. This approach not therefore only fixes the spacetime dimensionality at 3+1, but also imposes the compactification of extra dimensions in higher dimensional theor… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1303.5634v1-abstract-full').style.display = 'inline'; document.getElementById('1303.5634v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1303.5634v1-abstract-full" style="display: none;"> It is shown by very simple arguments that the observed 3+1 dimensionality of spacetime may be understood on the basis of four fundamental principles of physics namely, Causality, General Covariance, Gauge Invariance and Renormalizability. This approach not therefore only fixes the spacetime dimensionality at 3+1, but also imposes the compactification of extra dimensions in higher dimensional theories based on these principles such as string theory as an internal consistency requirement rather than an external imposition. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1303.5634v1-abstract-full').style.display = 'none'; document.getElementById('1303.5634v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 March, 2013; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2013. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">six pages, 0ne figure</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Orissa Journal of Physics, vol XII, 174-179, 2005 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1211.7041">arXiv:1211.7041</a> <span> [<a href="https://arxiv.org/pdf/1211.7041">pdf</a>, <a href="https://arxiv.org/ps/1211.7041">ps</a>, <a href="https://arxiv.org/format/1211.7041">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Atomic and Molecular Clusters">physics.atm-clus</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> </div> <p class="title is-5 mathjax"> Pumping K-Alpha Resonance Fluorescence by Monochromatic X-Ray Sources </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Nahar%2C+S+N">Sultana N. Nahar</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">Anil K. Pradhan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1211.7041v1-abstract-short" style="display: inline;"> We demonstrate the correspondence between theoretically calculated K-shell resonances lying below the K-edge in multiple ionization states of an element (Pradhan et al. 2009), and recently observed K-alpha resonances in high-intensity X-ray free-electron laser (XFEL) plasmas (Vinko et al. 2012). Resonant absorptions in aluminum ions are computed and found to reproduce experimentally observed featu… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1211.7041v1-abstract-full').style.display = 'inline'; document.getElementById('1211.7041v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1211.7041v1-abstract-full" style="display: none;"> We demonstrate the correspondence between theoretically calculated K-shell resonances lying below the K-edge in multiple ionization states of an element (Pradhan et al. 2009), and recently observed K-alpha resonances in high-intensity X-ray free-electron laser (XFEL) plasmas (Vinko et al. 2012). Resonant absorptions in aluminum ions are computed and found to reproduce experimentally observed features. Results are also presented for titanium for possible observation of K-alpha resonances in the 4.5-5.0 keV energy range. A possibly sustainable excitation mechanism for K-alpha resonance fluorescence might be implemented using two monochromatic X-ray beams tuned to the K-edge and the K-alpha resonant energies simultaneously. This targeted ionization/excitation would create inner-shell vacancies via Auger decay, as well as pump K-alpha resonances. The required X-ray fluence to achieve resonance fluorescence would evidently be much less than in the XFEL experiments, and might enable novel biomedical applications. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1211.7041v1-abstract-full').style.display = 'none'; document.getElementById('1211.7041v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 29 November, 2012; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2012. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">5 pages, 4 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1206.6095">arXiv:1206.6095</a> <span> [<a href="https://arxiv.org/pdf/1206.6095">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="History and Philosophy of Physics">physics.hist-ph</span> </div> </div> <p class="title is-5 mathjax"> Psychophysical Interpretation of Quantum theory </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Pradhan%2C+R+K">Rajat K Pradhan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1206.6095v2-abstract-short" style="display: inline;"> It is shown that the formalism of quantum theory naturally incorporates the psychophysical parallelism and thereby interprets itself, if the subjective aspects are taken as equal partners alongside the objective aspects as determinants of Reality as a Whole. The inevitable interplay of the subject (observer) and the object (observed) in making up Reality is brought out succinctly through a compreh… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1206.6095v2-abstract-full').style.display = 'inline'; document.getElementById('1206.6095v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1206.6095v2-abstract-full" style="display: none;"> It is shown that the formalism of quantum theory naturally incorporates the psychophysical parallelism and thereby interprets itself, if the subjective aspects are taken as equal partners alongside the objective aspects as determinants of Reality as a Whole. The inevitable interplay of the subject (observer) and the object (observed) in making up Reality is brought out succinctly through a comprehensive psychophysical interpretation which includes in its bosom the truths of many of the major interpretations proposed so far as essential ingredients. At the heart of this novel approach lies the interpretation of the complex conjugate quantities such as the conjugate wave function Ψ*(r, t), the bra vector <Ψ|, and the adjoint operator A† etc. as representing the subjective counterparts of the corresponding objective aspects represented by the wave function Ψ(r, t), the ket vector |Ψ>, and the observable A etc. respectively. This brings out the psycho-physical parallelism lying hidden in the quantum mechanical formalism in a quite straightforward manner. The measurement process is shown to be a two-step process comprising objective interaction through the retarded waves and subjective observation leading to rise of knowledge through the advanced waves. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1206.6095v2-abstract-full').style.display = 'none'; document.getElementById('1206.6095v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 16 December, 2012; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 25 June, 2012; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2012. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">published version</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Neuroquantology, vol. 10, (4), 629-645, 2012 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1204.0812">arXiv:1204.0812</a> <span> [<a href="https://arxiv.org/pdf/1204.0812">pdf</a>, <a href="https://arxiv.org/ps/1204.0812">ps</a>, <a href="https://arxiv.org/format/1204.0812">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Cosmology and Nongalactic Astrophysics">astro-ph.CO</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1111/j.1745-3933.2012.01252.x">10.1111/j.1745-3933.2012.01252.x <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Improved collision strengths and line ratios for forbidden [O III] far-infrared and optical lines </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Palay%2C+E">Ethan Palay</a>, <a href="/search/physics?searchtype=author&query=Nahar%2C+S+N">Sultana N. Nahar</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">Anil K. Pradhan</a>, <a href="/search/physics?searchtype=author&query=Eissner%2C+W">W. Eissner</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1204.0812v1-abstract-short" style="display: inline;"> Far-infrared and optical [O III] lines are useful temeprature-density diagnostics of nebular as well as dust obscured astrophysical sources. Fine structure transitions among the ground state levels 1s^22s^22p^3 \ ^3P_{0,1,2} give rise to the 52 and 88 micron lines, whereas transitions among the $^3P_{0,1,2}, ,^1D_2, ^1S_0$ levels yield the well-known optical lines 4363, 4959 and 5007 Angstroms. Th… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1204.0812v1-abstract-full').style.display = 'inline'; document.getElementById('1204.0812v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1204.0812v1-abstract-full" style="display: none;"> Far-infrared and optical [O III] lines are useful temeprature-density diagnostics of nebular as well as dust obscured astrophysical sources. Fine structure transitions among the ground state levels 1s^22s^22p^3 \ ^3P_{0,1,2} give rise to the 52 and 88 micron lines, whereas transitions among the $^3P_{0,1,2}, ,^1D_2, ^1S_0$ levels yield the well-known optical lines 4363, 4959 and 5007 Angstroms. These lines are excited primarily by electron impact excitation. But despite their importance in nebular diagnostics collision strengths for the associated fine structure transitions have not been computed taking full account of relativistic effects. We present Breit-Pauli R-matrix calculations for the collision strengths with highly resolved resonance structures. We find significant differences of up to 20% in the Maxwellian averaged rate coefficients from previous works. We also tabulate these to lower temperatures down to 100 K to enable determination of physical conditions in cold dusty environments such photo-dissociation regions and ultra-luminous infrared galaxies observed with the Herschel space observatory. We also examine the effect of improved collision strengths on temperature and density sensitive line ratios. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1204.0812v1-abstract-full').style.display = 'none'; document.getElementById('1204.0812v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 3 April, 2012; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2012. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Letter in press, Monthly Notices of Royal Astronomical Society, 5 pages, 6 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1111.5227">arXiv:1111.5227</a> <span> [<a href="https://arxiv.org/pdf/1111.5227">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="General Physics">physics.gen-ph</span> </div> </div> <p class="title is-5 mathjax"> Quantum Anti-Zeno Treatment of Zeno-type Sleep Disorders </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Pradhan%2C+R+K">Rajat Kumar Pradhan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1111.5227v1-abstract-short" style="display: inline;"> It is proposed that for those sleep disorders of psychological origin which can be considered to be a Quantum Zeno Effect-type phenomenon of persistence in the waking state due to the inhibition of the transition to the Deep Sleep state, the treatment may very well lie in the application of the principle of accelerating the decay by the introduction of a third state which facilitates the transitio… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1111.5227v1-abstract-full').style.display = 'inline'; document.getElementById('1111.5227v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1111.5227v1-abstract-full" style="display: none;"> It is proposed that for those sleep disorders of psychological origin which can be considered to be a Quantum Zeno Effect-type phenomenon of persistence in the waking state due to the inhibition of the transition to the Deep Sleep state, the treatment may very well lie in the application of the principle of accelerating the decay by the introduction of a third state which facilitates the transition as realized in the Quantum Anti-Zeno effect. Steps of practical therapeutic implementation of the program are delineated. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1111.5227v1-abstract-full').style.display = 'none'; document.getElementById('1111.5227v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 November, 2011; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2011. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Interdisciplinary, 7 pages, 1 figure, invited article submitted to the journal "SLEEP DISORDERS"</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1104.2881">arXiv:1104.2881</a> <span> [<a href="https://arxiv.org/pdf/1104.2881">pdf</a>, <a href="https://arxiv.org/ps/1104.2881">ps</a>, <a href="https://arxiv.org/format/1104.2881">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Solar and Stellar Astrophysics">astro-ph.SR</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevA.83.053417">10.1103/PhysRevA.83.053417 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Highly Excited Core Resonances in Photoionization of Fe XVII : Implications for Plasma Opacities </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Nahar%2C+S+N">Sultana N. Nahar</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">Anil K. Pradhan</a>, <a href="/search/physics?searchtype=author&query=Chen%2C+G">Guo-Xin Chen</a>, <a href="/search/physics?searchtype=author&query=Eissner%2C+W">Werner Eissner</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1104.2881v1-abstract-short" style="display: inline;"> A comprehensive study of high-accuracy photoionization cross sections is carried out using the relativistic Breit-Pauli R-matrix (BPRM) method for (hnu + Fe XVII --> Fe XVIII + e). Owing to its importance in high-temperature plasmas the calculations cover a large energy range, particularly the myriad photoexciation-of-core (PEC) resonances including the n = 3 levels not heretofore considered. The… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1104.2881v1-abstract-full').style.display = 'inline'; document.getElementById('1104.2881v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1104.2881v1-abstract-full" style="display: none;"> A comprehensive study of high-accuracy photoionization cross sections is carried out using the relativistic Breit-Pauli R-matrix (BPRM) method for (hnu + Fe XVII --> Fe XVIII + e). Owing to its importance in high-temperature plasmas the calculations cover a large energy range, particularly the myriad photoexciation-of-core (PEC) resonances including the n = 3 levels not heretofore considered. The calculations employ a close coupling wave function expansion of 60 levels of the core ion Fe XVIII ranging over a wide energy range of nearly 900 eV between the n = 2 and n = 3 levels. Strong coupling effects due to dipole transition arrays 2p^5 --> 2p^4 (3s,3d) manifest themselves as large PEC resonances throughout this range, and enhance the effective photoionization cross sections orders of magnitude above the background. Comparisons with the erstwhile Opacity Project (OP) and other previous calculations shows that the currently available cross sections considerably underestimate the bound-free cross sections. A level-identification scheme is used for spectroscopic designation of the 454 bound fine structure levels of Fe XVII. Level-specific photoionization cross sections are computed for all levels. In addition, partial cross sections for leaving the core ion Fe XVII in the ground state are also obtained. These results should be relevant to modeling of astrophysical and laboratory plasma sources requiring (i) photoionization rates, (ii) extensive non-local-thermodynamic-equilibrium models, (iii) total unified electron-ion recombination rates including radiative and dielectronic recombination, and (iv) plasma opacities. We particularly examine PEC and non-PEC resonance strengths and emphasize their expanded role to incorporate inner-shell excitations for improved opacities, as shown by the computed monochromatic opacity of Fe XVII. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1104.2881v1-abstract-full').style.display = 'none'; document.getElementById('1104.2881v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 14 April, 2011; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2011. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">12 pages, 5 figures, Physical Review A (in press)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/0908.1365">arXiv:0908.1365</a> <span> [<a href="https://arxiv.org/pdf/0908.1365">pdf</a>, <a href="https://arxiv.org/ps/0908.1365">ps</a>, <a href="https://arxiv.org/format/0908.1365">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="General Physics">physics.gen-ph</span> </div> </div> <p class="title is-5 mathjax"> On Reality of Tachyonic de Broglie Waves </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Pradhan%2C+R+K">Rajat K. Pradhan</a>, <a href="/search/physics?searchtype=author&query=Singh%2C+L+P">Lambodar P. Singh</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="0908.1365v2-abstract-short" style="display: inline;"> We investigate the tachyonic nature of the de Broglie matter waves associated with a free quantum object to show that granting reality to them would lend completeness to the quantum description of reality. Basing on the robustness of the well known Einstein-de Broglie reciprocal relation between the phase and the particle velocities, we extend the concept of complementarity to them and thereby p… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0908.1365v2-abstract-full').style.display = 'inline'; document.getElementById('0908.1365v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="0908.1365v2-abstract-full" style="display: none;"> We investigate the tachyonic nature of the de Broglie matter waves associated with a free quantum object to show that granting reality to them would lend completeness to the quantum description of reality. Basing on the robustness of the well known Einstein-de Broglie reciprocal relation between the phase and the particle velocities, we extend the concept of complementarity to them and thereby propose a complementary relation between a bradyon and its corresponding tachyon (i.e. the associated matter wave) to endow the tachyons with a degree of reality, at least on par with the bradyons, within the current framework of quantum physics and extended relativity. The duality is used to argue that because of the observed localised nature of bradyons, tachyons should always be pervasive or global in character and thus, there can be no point-like tachyons. A common misconception regarding the nonrelativistic limit of the Einstein-de Broglie relation is pointed out and the consequent error of long standing is remedied. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0908.1365v2-abstract-full').style.display = 'none'; document.getElementById('0908.1365v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 11 August, 2009; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 10 August, 2009; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2009. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">19 pages, no figures, submission date 10/08/2009. Typos corrected. Few small changes made in the introduction. An earlier version of the paper with almost the same contents but with the title : 'On the Reality of Tachyonic Matter waves' appeared in the Orissa Journal of Physics (OJP), vol. 16, 1, 149 - 164,(2009)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/0907.4971">arXiv:0907.4971</a> <span> [<a href="https://arxiv.org/pdf/0907.4971">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="General Physics">physics.gen-ph</span> </div> </div> <p class="title is-5 mathjax"> Quantum Mechanics Of Consciousness </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Pradhan%2C+R+K">Rajat Kumar Pradhan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="0907.4971v2-abstract-short" style="display: inline;"> A phenomenological approach using the states of spin-like observables is developed to understand the nature of consciousness and the totality of experience. The three states of consciousness are taken to form the triplet of eigenstates of a spin-one entity and are derived as the triplet resulting from the composition of two spins by treating the subject and the object as interacting two-state, s… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0907.4971v2-abstract-full').style.display = 'inline'; document.getElementById('0907.4971v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="0907.4971v2-abstract-full" style="display: none;"> A phenomenological approach using the states of spin-like observables is developed to understand the nature of consciousness and the totality of experience. The three states of consciousness are taken to form the triplet of eigenstates of a spin-one entity and are derived as the triplet resulting from the composition of two spins by treating the subject and the object as interacting two-state, spin-half systems with external and internal projections. The state of deep sleep is analysed in the light of this phenomenological approach and a novel understanding of the status of the individual consciousness in this state is obtained. The resulting fourth state i.e. the singlet state is interpreted to correspond to the superconscious state of intuitive experience and is justified by invoking the concept of the universal consciousness as the underlying source of all individual states of experience. It is proposed that the individual experiences result from the operations of four individualizing observables which project out the individual from the universal. The one-to-one correspondence between the individual and the universal states of experience is brought out and their identity in the fourth state is established by showing that all individualizing quantum numbers become zero in this state leaving no trace of any individuality. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0907.4971v2-abstract-full').style.display = 'none'; document.getElementById('0907.4971v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 29 July, 2009; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 28 July, 2009; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2009. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">37 pages, no figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Neuroquantology, vol. 8, No. 3, (2010), 262-278 ( title changed to "Subject-Object Duality and States of Consciousness: A Quantum Approach" </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/0711.4134">arXiv:0711.4134</a> <span> [<a href="https://arxiv.org/pdf/0711.4134">pdf</a>, <a href="https://arxiv.org/ps/0711.4134">ps</a>, <a href="https://arxiv.org/format/0711.4134">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevA.76.062504">10.1103/PhysRevA.76.062504 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A study of the breakdown of the quasi-static approximation at high densities and its effect on the helium-like K ALPHA complex of nickel, iron, and calcium </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Oelgoetz%2C+J">Justin Oelgoetz</a>, <a href="/search/physics?searchtype=author&query=Fontes%2C+C+J">Christopher J. Fontes</a>, <a href="/search/physics?searchtype=author&query=Zhang%2C+H+L">Hong Lin Zhang</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">Anil K. Pradhan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="0711.4134v1-abstract-short" style="display: inline;"> The General Spectral Modeling (GSM) code employs the quasi-static approximation, a standard, low-density methodology that assumes the ionization balance is separable from a determination of the excited-state populations that give rise to the spectra. GSM also allows for some states to be treated only as contributions to effective rates. While these two approximations are known to be valid at low… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0711.4134v1-abstract-full').style.display = 'inline'; document.getElementById('0711.4134v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="0711.4134v1-abstract-full" style="display: none;"> The General Spectral Modeling (GSM) code employs the quasi-static approximation, a standard, low-density methodology that assumes the ionization balance is separable from a determination of the excited-state populations that give rise to the spectra. GSM also allows for some states to be treated only as contributions to effective rates. While these two approximations are known to be valid at low densities, this work investigates using such methods to model high-density, non-LTE emission spectra and determines at what point the approximations break down by comparing to spectra produced by the LANL code ATOMIC which makes no such approximations. As both approximations are used by other astrophysical and low-density modeling codes, the results should be of broad interest. He-like K$α$ emission spectra are presented for Ni, Fe, and Ca, in order to gauge the effect of both approximations employed in GSM. This work confirms that at and above the temperature of maximum abundance of the He-like ionization stage, the range of validity for both approximations is sufficient for modeling the low- and moderate-density regimes one typically finds in astrophysical and magnetically confined fusion plasmas. However, a breakdown does occur for high densities; we obtain quantitative limits that are significantly higher than previous works. This work demonstrates that, while the range of validity for both approximations is sufficient to predict the density-dependent quenching of the z line, the approximations break down at higher densities. Thus these approximations should be used with greater care when modeling high-density plasmas such as those found in inertial confinement fusion and electromagnetic pinch devices. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0711.4134v1-abstract-full').style.display = 'none'; document.getElementById('0711.4134v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 27 November, 2007; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2007. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted by Physical Review A (http://pra.aps.org/). 11 pages + LANL cover, 5 figures. Will update citation information as it becomes available. Abbreviated abstract is listed here</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Report number:</span> LA-UR-07-6501 </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys.Rev.A76:062504,2007 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/0709.0740">arXiv:0709.0740</a> <span> [<a href="https://arxiv.org/pdf/0709.0740">pdf</a>, <a href="https://arxiv.org/ps/0709.0740">ps</a>, <a href="https://arxiv.org/format/0709.0740">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1111/j.1365-2966.2007.12410.x">10.1111/j.1365-2966.2007.12410.x <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> High-temperature behaviour of the helium-like K ALPHA G ratio: the effect of improved recombination rate coefficients for calcium, iron, and nickel </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Oelgoetz%2C+J">J. Oelgoetz</a>, <a href="/search/physics?searchtype=author&query=Fontes%2C+C+J">C. J. Fontes</a>, <a href="/search/physics?searchtype=author&query=Zhang%2C+H+L">H. L. Zhang</a>, <a href="/search/physics?searchtype=author&query=Montenegro%2C+M">M. Montenegro</a>, <a href="/search/physics?searchtype=author&query=Nahar%2C+S+N">S. N. Nahar</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">A. K. Pradhan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="0709.0740v2-abstract-short" style="display: inline;"> It is shown that above the temperature of maximum abundance, recombination rates into the excited states of He-like ions that are calculated using earlier, more approximate methods differ markedly from rates obtained from recent distorted-wave and R-Matrix calculations (unified recombination rate coefficients) for Ca, Fe, and Ni. The present rates lead to G ratios that are greatly lower than tho… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0709.0740v2-abstract-full').style.display = 'inline'; document.getElementById('0709.0740v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="0709.0740v2-abstract-full" style="display: none;"> It is shown that above the temperature of maximum abundance, recombination rates into the excited states of He-like ions that are calculated using earlier, more approximate methods differ markedly from rates obtained from recent distorted-wave and R-Matrix calculations (unified recombination rate coefficients) for Ca, Fe, and Ni. The present rates lead to G ratios that are greatly lower than those resulting from the more approximate rates in previous works, by up to a factor of six at high electron temperatures. Excellent agreement between the distorted-wave and the R-Matrix rates, as well as excellent agreement in the G ratios calculated from them, provides support for the accuracy of these new values which have a broad applicability to the modelling and interpreting of X-ray spectra from a variety of astrophysical and laboratory sources. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('0709.0740v2-abstract-full').style.display = 'none'; document.getElementById('0709.0740v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 15 November, 2007; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 5 September, 2007; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2007. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">11 pages including LANL cover, 6 figures. Minor typos corrected to conform to the version that will appear in print in MNRAS. The definitive version is available at http://www.blackwellsynergy.com. Specifically http://www.blackwell-synergy.com/doi/abs/10.1111/j.1365-2966.2007.12410.x</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Report number:</span> LA-UR-07-3112 </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> MNRAS 382, 761--769 (2007) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/astro-ph/0408065">arXiv:astro-ph/0408065</a> <span> [<a href="https://arxiv.org/pdf/astro-ph/0408065">pdf</a>, <a href="https://arxiv.org/ps/astro-ph/0408065">ps</a>, <a href="https://arxiv.org/format/astro-ph/0408065">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1111/j.1365-2966.2004.08269.x">10.1111/j.1365-2966.2004.08269.x <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The 6.7 keV KALPHA complex of He-like iron in transient plasmas </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Oelgoetz%2C+J">Justin Oelgoetz</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">Anil K. Pradhan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="astro-ph/0408065v1-abstract-short" style="display: inline;"> Time dependent numerical simulations of the K ALPHA complex of Fe XXV are carried out as a function of temperature/density/radiation field variations in high-temperature astrophysical and laboratory plasmas. In addition to several well known features, the transient and steady state spectra reveal the effects due to (a) time-dependent thermal and non-thermal radiation fields, (b) photo and collis… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0408065v1-abstract-full').style.display = 'inline'; document.getElementById('astro-ph/0408065v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="astro-ph/0408065v1-abstract-full" style="display: none;"> Time dependent numerical simulations of the K ALPHA complex of Fe XXV are carried out as a function of temperature/density/radiation field variations in high-temperature astrophysical and laboratory plasmas. In addition to several well known features, the transient and steady state spectra reveal the effects due to (a) time-dependent thermal and non-thermal radiation fields, (b) photo and collisional excitation and ionization, and (c) high densities, on the `quartet' of principal w,x,y,z lines, and dielectronic satellites. The highly detailed models show precisely how, assuming a temporal-temperature correlation, the X-ray intensity varies between 6.6 - 6.7 keV and undergoes a `spectral inversion' in the w and z line intensities, characterizing an ionization or a recombination dominated plasma. The dielectronic satellite intensities are the most temperature dependent features, but insensitive to density variations, and significantly contribute to the K ALPHA complex for T < 6.7 keV leading to asymmetric profiles. The 6.7 keV K ALPHA complex should be a potential diagnostic of X-ray flares in AGN, afterglows in gamma-ray bursts, and other non-equilibrium sources with the high-resolution measurements possible from the upcoming mission Astro-E2. It is also shown that high electron densities attenuate the line intensities in simulations relevant to laboratory plasmas, such as in inertial confinement fusion, laser, or magnetic Z-pinch devices. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0408065v1-abstract-full').style.display = 'none'; document.getElementById('astro-ph/0408065v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 3 August, 2004; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2004. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">13 pages, 4 figures, 1 postscript coversheet. This is a preprint of an article accepted for publication in the Monthly Notices of the Royal Astronomical Society</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Report number:</span> LA-UR-04-4218 </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Mon.Not.Roy.Astron.Soc.354:1093-1102,2004 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/astro-ph/0310624">arXiv:astro-ph/0310624</a> <span> [<a href="https://arxiv.org/pdf/astro-ph/0310624">pdf</a>, <a href="https://arxiv.org/ps/astro-ph/0310624">ps</a>, <a href="https://arxiv.org/format/astro-ph/0310624">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1016/j.radphyschem.2003.12.019">10.1016/j.radphyschem.2003.12.019 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Self-Consistent R-matrix Approach To Photoionization And Unified Electron-Ion Recombination </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Nahar%2C+S+N">Sultana N. Nahar</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">Anil K. Pradhan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="astro-ph/0310624v1-abstract-short" style="display: inline;"> A unified scheme using the R-matrix method has been developed for electron-ion recombination subsuming heretofore separate treatments of radiative and dielectronic recombination (RR and DR). The ab initio coupled channel approach unifies resonant and non-resonant phenomena, and enables a general and self-consistent treatment of photoionization and electron-ion recombination employing idential wa… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0310624v1-abstract-full').style.display = 'inline'; document.getElementById('astro-ph/0310624v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="astro-ph/0310624v1-abstract-full" style="display: none;"> A unified scheme using the R-matrix method has been developed for electron-ion recombination subsuming heretofore separate treatments of radiative and dielectronic recombination (RR and DR). The ab initio coupled channel approach unifies resonant and non-resonant phenomena, and enables a general and self-consistent treatment of photoionization and electron-ion recombination employing idential wavefunction expansion. Detailed balance takes account of interference effects due to resonances in cross sections, calculated explicitly for a large number of recombined (e+ion) bound levels over extended energy regions. The theory of DR by Bell and Seaton is adapted for high-n resonances in the region below series limits. The R-matrix method is employed for (A) partial and total photoionization and photorecombination cross sections of (e+ion) bound levels, and (B) DR and (e+ion) scattering cross sections. Relativistic effects and fine structure are considered in the Breit-Pauli approximation. Effects such as radiation damping may be taken into account where necessary. Unfiied recombination cross sections are in excellent agreement with measurements on ion storage rings to about 10-20%. In addition to high accuracy, the strengths of the method are: (I) both total and level-specific cross sections and rate coefficients are obtained, and (II) a single (e+ion) recombination rate coefficient for any given atom or ion is obtained over the entire temperature range of practical importance in laboratory and astrophysical plasmas, (III) self-consistent results are obtained for photoionization and recombination; comprehensive datasets have been computed for over 50 atoms and ions. Selected data are presented for iron ions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0310624v1-abstract-full').style.display = 'none'; document.getElementById('astro-ph/0310624v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 October, 2003; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2003. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">33 pages, 13 figures, Review in "Radiation Processes In Physics and Chemistry", Elsevier (in press). Postscript file with higher resolution figures at http://www.astronomy.ohio-state.edu/~pradhan/pr.ps</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Radiat.Phys.Chem. 70 (2004) 323-344 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/astro-ph/0302238">arXiv:astro-ph/0302238</a> <span> [<a href="https://arxiv.org/pdf/astro-ph/0302238">pdf</a>, <a href="https://arxiv.org/ps/astro-ph/0302238">ps</a>, <a href="https://arxiv.org/format/astro-ph/0302238">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1046/j.1365-8711.2003.06513.x">10.1046/j.1365-8711.2003.06513.x <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> X-ray absorption via K-alpha resonance complexes in oxygen ions </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">Anil K. Pradhan</a>, <a href="/search/physics?searchtype=author&query=Chen%2C+G+X">Guo Xin Chen</a>, <a href="/search/physics?searchtype=author&query=Delahaye%2C+F">Franck Delahaye</a>, <a href="/search/physics?searchtype=author&query=Nahar%2C+S+N">Sultana N. Nahar</a>, <a href="/search/physics?searchtype=author&query=Oelgoetz%2C+J">Justin Oelgoetz</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="astro-ph/0302238v1-abstract-short" style="display: inline;"> The K-alpha resonance complexes in oxygen ions O I - O VI are theoretically computed and resonance oscillator strengths and wavelengths are presented. The highly resolved photoionization cross sections, with relativistic fine structure, are computed in the coupled channel approximation using the Breit-Pauli R-matrix method. A number of strong K-alpha resonances are found to be appreciable, with… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0302238v1-abstract-full').style.display = 'inline'; document.getElementById('astro-ph/0302238v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="astro-ph/0302238v1-abstract-full" style="display: none;"> The K-alpha resonance complexes in oxygen ions O I - O VI are theoretically computed and resonance oscillator strengths and wavelengths are presented. The highly resolved photoionization cross sections, with relativistic fine structure, are computed in the coupled channel approximation using the Breit-Pauli R-matrix method. A number of strong K-alpha resonances are found to be appreciable, with resonance oscillator strengths f_r > 0.1. The K-alpha resonance wavelengths of O I-O VI lie in a relatively narrow wavelength range 22 - 23.5 A, and the X-ray opacity in this region should therefore be significantly affected by K --> L transitions in oxygen. The results should be useful in the interpretation of soft X-ray spectra observed from Chandra and XMM-Newton. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0302238v1-abstract-full').style.display = 'none'; document.getElementById('astro-ph/0302238v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 12 February, 2003; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2003. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Monthly Notices of Roy. Astro. Soc. (in press), 10 pgs. 1 figure</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Mon.Not.Roy.Astron.Soc.341:1268-1271,2003 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/astro-ph/0204116">arXiv:astro-ph/0204116</a> <span> [<a href="https://arxiv.org/pdf/astro-ph/0204116">pdf</a>, <a href="https://arxiv.org/ps/astro-ph/0204116">ps</a>, <a href="https://arxiv.org/format/astro-ph/0204116">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> </div> <p class="title is-5 mathjax"> X-Ray Resonance Opacity of Oxygen and Iron in AGN MCG--6-30-15 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">Anil K. Pradhan</a>, <a href="/search/physics?searchtype=author&query=Chen%2C+G">Guo-Xin Chen</a>, <a href="/search/physics?searchtype=author&query=Delahaye%2C+F">Franck Delahaye</a>, <a href="/search/physics?searchtype=author&query=Nahar%2C+S+N">Sultana N. Nahar</a>, <a href="/search/physics?searchtype=author&query=Oelgoetz%2C+J">Justin Oelgoetz</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="astro-ph/0204116v2-abstract-short" style="display: inline;"> Theoretical differential oscillator strengths related to monochromatic opacity due to K- and L-shell absorption from oxygen and iron ions are directly compared with the Chandra and Xmm-Newton spectra of Seyfert~1 galaxy MCG--6-30-15. We compute the highly resolved continuum with resonances due to O I - VI and Fe XVI. It is found that the KLn (n --> infty) resonance series limits in O VI, and the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0204116v2-abstract-full').style.display = 'inline'; document.getElementById('astro-ph/0204116v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="astro-ph/0204116v2-abstract-full" style="display: none;"> Theoretical differential oscillator strengths related to monochromatic opacity due to K- and L-shell absorption from oxygen and iron ions are directly compared with the Chandra and Xmm-Newton spectra of Seyfert~1 galaxy MCG--6-30-15. We compute the highly resolved continuum with resonances due to O I - VI and Fe XVI. It is found that the KLn (n --> infty) resonance series limits in O VI, and the lowest LMM resonance in Fe XVI, lie at the prominent 17.5 A break in the observed spectra. We also calculate and identify, for the first time, the observed gap in spectral flux at 22-23 A in the Chandra spectra due to K --> L resonant absorption features from all O-ions O I - VI, potentially leading to abundance determination of several or all ionization stages; similar signature gaps may be predicted due to other elements. The precise atomic parameters are computed in the relativistic close coupling approximation using the Breit-Pauli R-matrix method. The new X-ray opacities might possibly distinguish between models of a dusty warm absorber, and/or gravitational redshift and broadening due to a massive black hole in MCG--6-30-15. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0204116v2-abstract-full').style.display = 'none'; document.getElementById('astro-ph/0204116v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 9 April, 2002; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 8 April, 2002; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2002. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">16 pages, 3 figures. Fig. 2 is in color, available from http://www.astronomy.ohio-state.edu/~oelgoetz/xop-mcg6.html</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/astro-ph/0201535">arXiv:astro-ph/0201535</a> <span> [<a href="https://arxiv.org/pdf/astro-ph/0201535">pdf</a>, <a href="https://arxiv.org/ps/astro-ph/0201535">ps</a>, <a href="https://arxiv.org/format/astro-ph/0201535">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1088/0953-4075/35/16/301">10.1088/0953-4075/35/16/301 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Electron impact excitation of helium-like oxygen up to n = 4 levels including radiation damping </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Delahaye%2C+F">Franck Delahaye</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">Anil K. Pradhan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="astro-ph/0201535v1-abstract-short" style="display: inline;"> The primary X-ray diagnostic lines in He-like ions are mainly excited by electron impact from the ground level to the n = 2 levels, but at high temperatures n > 2 levels are also excited. In order to describe the atomic processes more completely collision strengths are computed for OVII including for the first time all of the following: (i) relativistic fine structure, (ii) levels up to the n =… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0201535v1-abstract-full').style.display = 'inline'; document.getElementById('astro-ph/0201535v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="astro-ph/0201535v1-abstract-full" style="display: none;"> The primary X-ray diagnostic lines in He-like ions are mainly excited by electron impact from the ground level to the n = 2 levels, but at high temperatures n > 2 levels are also excited. In order to describe the atomic processes more completely collision strengths are computed for OVII including for the first time all of the following: (i) relativistic fine structure, (ii) levels up to the n = 4, and (iii) radiation damping of autoionizing resonances. The calculations are carried out using the Breit-Pauli R-matrix (BPRM) method with a 31-level eigenfunction expansion. Resonance structures in collision strengths are delineated in detail up to the n = 4 thresholds. For highly charged He-like ions radiation damping of autoionizing resonances is known to be significant. We investigate this effect in detail and find that while resonances are discernibly damped radiatively as the series limit n --> infty is approached from below, the overall effect on effective cross sections and rate coefficients is found to be very small. Collision strengths for the principal lines important in X-ray plasma diagnostics, w,x,y and z, corresponding to the 4 transitions to the ground level 1s^2 (^1S_0) <-- 1s2p (^1P^o_1), 1s2p (^3P^o_2), 1s2p (^3P^o_1), 1s2s (^3S_1), are explicitly shown. It is found that the effective collision strength of the forbidden z-line is up to a factor of 4 higher at T < 10^6 K than previous values. This is likely to be of considerable importance in the diagnostics of photoionized astrophysical plasmas. Significant differences are also found with previous works for several other transitions. This work is carried out as part of the Iron Project-RmaX Network. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0201535v1-abstract-full').style.display = 'none'; document.getElementById('astro-ph/0201535v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 31 January, 2002; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2002. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">16 pages, 8 figures (3 in color), submitted to Journal of Physics B</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/astro-ph/0201513">arXiv:astro-ph/0201513</a> <span> [<a href="https://arxiv.org/pdf/astro-ph/0201513">pdf</a>, <a href="https://arxiv.org/ps/astro-ph/0201513">ps</a>, <a href="https://arxiv.org/format/astro-ph/0201513">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevLett.89.013202">10.1103/PhysRevLett.89.013202 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Influence of Resonances on Spectral Formation of X-Ray Lines in Fe XVII </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Chen%2C+G">Guo-Xin Chen</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">Anil K. Pradhan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="astro-ph/0201513v3-abstract-short" style="display: inline;"> New theoretical results from large-scale relativistic close coupling calculations reveal the precise effect of resonances in collisional excitation of x-ray lines of Ne-like Fe XVII. Employing the Breit-Pauli R-matrix method and a 89-level eigenfunction expansion including up to n = 4 levels shows significant resonance enhancement of the collision strengths of forbidden and intercombination tran… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0201513v3-abstract-full').style.display = 'inline'; document.getElementById('astro-ph/0201513v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="astro-ph/0201513v3-abstract-full" style="display: none;"> New theoretical results from large-scale relativistic close coupling calculations reveal the precise effect of resonances in collisional excitation of x-ray lines of Ne-like Fe XVII. Employing the Breit-Pauli R-matrix method and a 89-level eigenfunction expansion including up to n = 4 levels shows significant resonance enhancement of the collision strengths of forbidden and intercombination transitions. The present results differ from all previous calculations, heretofore without detailed resonance structures, and should help resolve longstanding discrepancies. In particular, the present line ratios of three benchmark diagnostic lines 3C, 3D, and 3E at 15.014, 15.265, and 15.456 A respectively, are in excellent agreement with two independent measurements on Electron-Beam-Ion-Traps [Laming et al, Astrophys. J, 545, L161 (2000) and Brown et al, Astrophys. J, 502, 1015 (1998)]. The strong energy dependence due to resonances in these and other cross sections is demonstrated for the first time. It is of general importance and strongly manifests itself in x-ray plasma diagnostics. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0201513v3-abstract-full').style.display = 'none'; document.getElementById('astro-ph/0201513v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 May, 2002; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 30 January, 2002; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2002. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Phys. Rev. Letters (in press), 6 pages, 2 figures in color</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys.Rev.Lett.89:013202,2002 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/astro-ph/0106330">arXiv:astro-ph/0106330</a> <span> [<a href="https://arxiv.org/pdf/astro-ph/0106330">pdf</a>, <a href="https://arxiv.org/ps/astro-ph/0106330">ps</a>, <a href="https://arxiv.org/format/astro-ph/0106330">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1046/j.1365-8711.2001.04980.x">10.1046/j.1365-8711.2001.04980.x <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The K-alpha complex of He-like iron with dielectronic satellites </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Oelgoetz%2C+J">Justin Oelgoetz</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">Anil K. Pradhan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="astro-ph/0106330v1-abstract-short" style="display: inline;"> It is shown that the dielectronic satellites (DES) dominate X-ray spectral formation in the 6.7 keV K-alpha complex of Fe XXV at temperatures below that of maximum abundance in collisional ionization equilibrium T_m. Owing to their extreme temperature sensitivity the DES are excellent spectral diagnostics for T < T_m in photoionized, colllisional, or hybrid plasmas; whereas the forbidden, interc… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0106330v1-abstract-full').style.display = 'inline'; document.getElementById('astro-ph/0106330v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="astro-ph/0106330v1-abstract-full" style="display: none;"> It is shown that the dielectronic satellites (DES) dominate X-ray spectral formation in the 6.7 keV K-alpha complex of Fe XXV at temperatures below that of maximum abundance in collisional ionization equilibrium T_m. Owing to their extreme temperature sensitivity the DES are excellent spectral diagnostics for T < T_m in photoionized, colllisional, or hybrid plasmas; whereas the forbidden, intercombination, and resonance lines of Fe XXV are not. A diagnostic line ratio GD(T) is defined including the DES and the lines, with parameters from new relativistic atomic calculations. The DES absorption resonance strengths may be obtained from differential oscillator strengths to possibly yield the Fe XXIV/Fe XXV column densities. The DES contribution to highly ionized Fe should be of interest for models of redward broadening of K-alpha features, ionized accretion discs, accretion flows, and K-alpha temporal-temperature variability in AGN. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0106330v1-abstract-full').style.display = 'none'; document.getElementById('astro-ph/0106330v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 June, 2001; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2001. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">5 pages, 4 Figs., submitted to MNRAS. High-resolution, full-size figures are available from http://www.astronomy.ohio-state.edu/~pradhan</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> MNRAS, 2001, 327, L42 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/astro-ph/0105459">arXiv:astro-ph/0105459</a> <span> [<a href="https://arxiv.org/pdf/astro-ph/0105459">pdf</a>, <a href="https://arxiv.org/ps/astro-ph/0105459">ps</a>, <a href="https://arxiv.org/format/astro-ph/0105459">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevLett.87.183201">10.1103/PhysRevLett.87.183201 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Relativistic fine structure and resonance effects in electron-ion recombination and excitation of (e + C IV) </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">Anil K. Pradhan</a>, <a href="/search/physics?searchtype=author&query=Chen%2C+G+X">Guo Xin Chen</a>, <a href="/search/physics?searchtype=author&query=Nahar%2C+S+N">Sultana N. Nahar</a>, <a href="/search/physics?searchtype=author&query=Zhang%2C+H+L">Hong Lin Zhang</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="astro-ph/0105459v2-abstract-short" style="display: inline;"> Relativistic close coupling calculations are reported for unified electronic recombination of (e + C IV) including non-resonant and resonant recombination processes, radiative and dielectronic recombination (RR and DR). Detailed comparison of the theoretical unified results with two recent experiments on ion storage rings (Mannervik etal. [1] and Schippers etal. [2]) shows very good agreement in… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0105459v2-abstract-full').style.display = 'inline'; document.getElementById('astro-ph/0105459v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="astro-ph/0105459v2-abstract-full" style="display: none;"> Relativistic close coupling calculations are reported for unified electronic recombination of (e + C IV) including non-resonant and resonant recombination processes, radiative and dielectronic recombination (RR and DR). Detailed comparison of the theoretical unified results with two recent experiments on ion storage rings (Mannervik etal. [1] and Schippers etal. [2]) shows very good agreement in the entire measured energy region 2s -- 2p with 2pnl resonances. The results benchmark theory and experiments to uncertainties of ~15%, and show that the resonant and the background cross sections are not an incoherent sum of separate RR and DR contributions. The limiting values of the DR cross sections, as n ---> infinity, are shown to correspond to those due to electron impact excitation (EIE) at the 2Po_(1/2,3/2) fine structure thresholds, delineated for the first time. The near-threshold 2s 2S_(1/2) - 2p 2Po_(1/2,3/2) EIE cross sections are also compared with recent experimental measurements. The demonstrated threshold fine structure and resonance effects should be of general importance in excitation and recombination of positive ions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0105459v2-abstract-full').style.display = 'none'; document.getElementById('astro-ph/0105459v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 28 August, 2001; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 25 May, 2001; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2001. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">7 pages, 3 figures; accepted in Phys. Rev. Letters, no change from submitted version</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys.Rev.Lett.87:183201,2001 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/astro-ph/0103178">arXiv:astro-ph/0103178</a> <span> [<a href="https://arxiv.org/pdf/astro-ph/0103178">pdf</a>, <a href="https://arxiv.org/ps/astro-ph/0103178">ps</a>, <a href="https://arxiv.org/format/astro-ph/0103178">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevA.64.032719">10.1103/PhysRevA.64.032719 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Relativistic close coupling calculations for photoionization and recombination of Ne-like Fe XVII </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Zhang%2C+H+L">Hong Lin Zhang</a>, <a href="/search/physics?searchtype=author&query=Nahar%2C+S+N">Sultana N. Nahar</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">Anil K. Pradhan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="astro-ph/0103178v1-abstract-short" style="display: inline;"> Relativistic and channel coupling effects in photoionization and unified electronic recombination of Fe XVII are demonstrated with an extensive 60-level close coupling calculation using the Breit-Pauli R-matrix method. Photoionization and (e + ion) recombination calculations are carried out for the total and the level-specific cross sections, including the ground and several hundred excited boun… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0103178v1-abstract-full').style.display = 'inline'; document.getElementById('astro-ph/0103178v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="astro-ph/0103178v1-abstract-full" style="display: none;"> Relativistic and channel coupling effects in photoionization and unified electronic recombination of Fe XVII are demonstrated with an extensive 60-level close coupling calculation using the Breit-Pauli R-matrix method. Photoionization and (e + ion) recombination calculations are carried out for the total and the level-specific cross sections, including the ground and several hundred excited bound levels of Fe XVII (up to fine structure levels with n = 10). The unified (e + ion) recombination calculations for (e + Fe XVIII --> Fe XVII) include both the non-resonant and resonant recombination (`radiative' and `dielectronic recombination' -- RR and DR). The low-energy and the high energy cross sections are compared from: (i) a 3-level calculation with 2s^2p^5 (^2P^o_{1/2,3/2}) and 2s2p^6 (^2S_{1/2}), and (ii) the first 60-level calculation with Δn > 0 coupled channels with spectroscopic 2s^2p^5, 2s2p^6, 2s^22p^4 3s, 3p, 3d, configurations, and a number of correlation configurations. Strong channel coupling effects are demonstrated throughout the energy ranges considered, in particular via giant photoexcitation-of-core (PEC) resonances due to L-M shell dipole transition arrays 2p^5 --> 2p^4 3s, 3d in Fe XIII that enhance effective cross sections by orders of magnitude. Comparison is made with previous theoretical and experimental works on photoionization and recombination that considered the relatively small low-energy region (i), and the weaker Δn = 0 couplings. While the 3-level results are inadequate, the present 60-level results should provide reasonably complete and accurate datasets for both photoionization and (e + ion) recombination of Fe~XVII in laboratory and astrophysical plasmas. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0103178v1-abstract-full').style.display = 'none'; document.getElementById('astro-ph/0103178v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 12 March, 2001; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2001. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">19 pages, 8 figures, Phys. Rev. A (submitted)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/astro-ph/0102107">arXiv:astro-ph/0102107</a> <span> [<a href="https://arxiv.org/pdf/astro-ph/0102107">pdf</a>, <a href="https://arxiv.org/ps/astro-ph/0102107">ps</a>, <a href="https://arxiv.org/format/astro-ph/0102107">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevA.63.060701">10.1103/PhysRevA.63.060701 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> K-shell dielectronic resonances in photoabsorption: differential oscillator strengths for Li-like C IV, O VI, and Fe XXIV </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Nahar%2C+S+N">Sultana N. Nahar</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">Anil K. Pradhan</a>, <a href="/search/physics?searchtype=author&query=Zhang%2C+H+L">Hong Lin Zhang</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="astro-ph/0102107v2-abstract-short" style="display: inline;"> Recently X-ray photoabsorption in KLL resonances of O VI was predicted [Pradhan, Astrophys.J. Lett. 545, L165 (2000)], and detected by the Chandra X-ray Observatory [Lee et al, Astrophys. J. {\it Lett.}, submitted]. The required resonance oscillator strengths f_r, are evaluated in terms of the differential oscillator strength df/de that relates bound and continuum absorption. We present the f_… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0102107v2-abstract-full').style.display = 'inline'; document.getElementById('astro-ph/0102107v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="astro-ph/0102107v2-abstract-full" style="display: none;"> Recently X-ray photoabsorption in KLL resonances of O VI was predicted [Pradhan, Astrophys.J. Lett. 545, L165 (2000)], and detected by the Chandra X-ray Observatory [Lee et al, Astrophys. J. {\it Lett.}, submitted]. The required resonance oscillator strengths f_r, are evaluated in terms of the differential oscillator strength df/de that relates bound and continuum absorption. We present the f_r values from radiatively damped and undamped photoionization cross sections for Li-like C,O, and Fe calculated using relativistic close coupling Breit-Pauli R-matrix method. The KLL resonances of interest here are: 1s2p (^3P^o) 2s [^4P^o_{1/2,3/2}, ^2P^o_{1/2,3/2}] and 1s2p (^1P^o) 2s [^2P^o_{1/2,3/2}]. The KLL photoabsorption resonances in Fe XXIV are fully resolved up to natural autoionization profiles for the first time. It is demonstrated that the undamped f_r independently yield the resonance radiative decay rates, and thereby provide a precise check on the resolution of photoionization calculations in general. The predicted photoabsorption features should be detectable by the X-ray space observatories and enable column densities in highly ionized astrophysical plasmas to be determined from the calculated f_r. The dielectronic satellites may appear as redward broadening of resonances lines in emission and absorption. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0102107v2-abstract-full').style.display = 'none'; document.getElementById('astro-ph/0102107v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 March, 2001; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 6 February, 2001; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2001. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">9 pages, 2 figurs, Phys. Rev. A, Rapid Communication (submitted)</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys.Rev.A63:060701,2001 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/astro-ph/0003411">arXiv:astro-ph/0003411</a> <span> [<a href="https://arxiv.org/pdf/astro-ph/0003411">pdf</a>, <a href="https://arxiv.org/ps/astro-ph/0003411">ps</a>, <a href="https://arxiv.org/format/astro-ph/0003411">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1086/317366">10.1086/317366 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Electron-Ion Recombination Rate Coefficients and Photoionization Cross Sections for Astrophysically Abundant Elements IV. Relativistic calculations for C IV and C V for UV and X-ray modeling </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Nahar%2C+S+N">Sultana N. Nahar</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">Anil K. Pradhan</a>, <a href="/search/physics?searchtype=author&query=Zhang%2C+H+L">Hong Lin Zhang</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="astro-ph/0003411v2-abstract-short" style="display: inline;"> The first complete set of unified cross sections and rate coefficients are calculated for photoionization and recombination of He- and Li-like ions using the relativistic Breit-Pauli R-matrix method. We present total, unified (e + ion) recombination rate coefficients for (e + C VI ---> C V) and (e + C V \longrightarrow C IV) including fine structure. Level-specific recombination rate coefficient… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0003411v2-abstract-full').style.display = 'inline'; document.getElementById('astro-ph/0003411v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="astro-ph/0003411v2-abstract-full" style="display: none;"> The first complete set of unified cross sections and rate coefficients are calculated for photoionization and recombination of He- and Li-like ions using the relativistic Breit-Pauli R-matrix method. We present total, unified (e + ion) recombination rate coefficients for (e + C VI ---> C V) and (e + C V \longrightarrow C IV) including fine structure. Level-specific recombination rate coefficients up to the n = 10 levels are also obtained for the first time; these differ considerably from the approximate rates currently available. Applications to recombination-cascade coefficients in X-ray spectral models of K-alpha emission from the important He-like ions is pointed out. The overall uncertainty in the total recombination rates should not exceed 10-20%. Ionization fractions for Carbon are recomputed in the coronal approximation using the new rates. The present (e + ion) recombination rate coefficients are compared with several sets of available data, including previous LS coupling results, and `experimentally derived' rate coefficients. The role of relativistic fine structure, resolution of resonances, radiation damping, and interference effects is discussed. Two general features of recombination rates are noted: (i) the non-resonant (radiative recombination) peak as E,T ---> 0, and the (ii) the high-T resonant (di-electronic recombination) peak. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0003411v2-abstract-full').style.display = 'none'; document.getElementById('astro-ph/0003411v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 June, 2000; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 27 March, 2000; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2000. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">38 pages, 10 figures, submitted to Astrophys. J. (Suppl)</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Astrophys.J.Suppl. 131 (2000) 375-390 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/astro-ph/0003410">arXiv:astro-ph/0003410</a> <span> [<a href="https://arxiv.org/pdf/astro-ph/0003410">pdf</a>, <a href="https://arxiv.org/ps/astro-ph/0003410">ps</a>, <a href="https://arxiv.org/format/astro-ph/0003410">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/aas:2000365">10.1051/aas:2000365 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Atomic data from the Iron Project.XLIV. Transition probabilities and line ratios for Fe VI with fluorescent excitation in planetary nebulae </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Chen%2C+G+X">Guo Xin Chen</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">Anil K. Pradhan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="astro-ph/0003410v1-abstract-short" style="display: inline;"> Relativistic atomic structure calculations for electric dipole E1, electric quadrupole E2 and magnetic dipole M1 transition probabilities among the first 80 fine-structure levels of Fe VI, dominated by configurations 3d^3, 3d^24s, and 3d^24p, are carried out using the Breit-Pauli version of the code Superstructure. Experimental energies are used to improve the accuracy of these transition probab… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0003410v1-abstract-full').style.display = 'inline'; document.getElementById('astro-ph/0003410v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="astro-ph/0003410v1-abstract-full" style="display: none;"> Relativistic atomic structure calculations for electric dipole E1, electric quadrupole E2 and magnetic dipole M1 transition probabilities among the first 80 fine-structure levels of Fe VI, dominated by configurations 3d^3, 3d^24s, and 3d^24p, are carried out using the Breit-Pauli version of the code Superstructure. Experimental energies are used to improve the accuracy of these transition probabilities. Employing the 80-level collision-radiative (CR) model with these dipole and forbidden transition probabilities, and Iron Project R-matrix collisional data, we present a number of [Fe VI] line ratios applicable to spectral diagnostics of photoionized H II regions. It is shown that continuum fluorescent excitation needs to be considered in CR models in order to interpret the observed line ratios of optical [Fe VI] lines in planetary nebulae NGC 6741, IC 351, and NGC 7662. The analysis leads to parametrization of line ratios as function of, and as constraints on, the electron density and temperature, as well as the effective radiation temperature of the central source and a geometrical dilution factor. The spectral diagnostics may also help ascertain observational uncertainties. The method may be generally applicable to other objects with intensive background radiation fields, such as novae and active galactic nuclei. The extensive new Iron Project radiative and collisional calculations enable a consistent analysis of many line ratios for the complex iron ions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0003410v1-abstract-full').style.display = 'none'; document.getElementById('astro-ph/0003410v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 27 March, 2000; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2000. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">25 pages, 8 figures, submitted to Astron.Astrophys. Suppl.Ser</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/astro-ph/0002356">arXiv:astro-ph/0002356</a> <span> [<a href="https://arxiv.org/pdf/astro-ph/0002356">pdf</a>, <a href="https://arxiv.org/ps/astro-ph/0002356">ps</a>, <a href="https://arxiv.org/format/astro-ph/0002356">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> </div> <p class="title is-5 mathjax"> The Iron Project </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">Anil K. Pradhan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="astro-ph/0002356v1-abstract-short" style="display: inline;"> Recent advances in theoretical atomic physics have enabled large-scale calculation of atomic parameters for a variety of atomic processes with high degree of precision. The development and application of these methods is the aim of the Iron Project. At present the primary focus is on collisional processes for all ions of iron, Fe I- FeXXVI, and other iron-peak elements; new work on radiative pro… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0002356v1-abstract-full').style.display = 'inline'; document.getElementById('astro-ph/0002356v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="astro-ph/0002356v1-abstract-full" style="display: none;"> Recent advances in theoretical atomic physics have enabled large-scale calculation of atomic parameters for a variety of atomic processes with high degree of precision. The development and application of these methods is the aim of the Iron Project. At present the primary focus is on collisional processes for all ions of iron, Fe I- FeXXVI, and other iron-peak elements; new work on radiative processes has also been initiated. Varied applications of the Iron Project work to X-ray astronomy are discussed, and more general applications to other spectral ranges are pointed out. The IP work forms the basis for more specialized projects such as the RMaX Project, and the work on photoionization/recombination, and aims to provide a comprehensive and self-consistent set of accurate collsional and radiative cross sections, and transition probabilities, within the framework of relativistic close coupling formulation using the Breit-Pauli R-Matrix method. An illustrative example is presented of how the IP data may be utilised in the formation of X-ray spectra of the K$α$ complex at 6.7 keV from He-like Fe XXV. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0002356v1-abstract-full').style.display = 'none'; document.getElementById('astro-ph/0002356v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 17 February, 2000; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2000. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">7 pagee, 2 figures. In Proceedings of the Symposium on Atomic Data Needs For X-Ray Astronomy, NASA GSFC, Dec. 16-17, 1999</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/astro-ph/0002230">arXiv:astro-ph/0002230</a> <span> [<a href="https://arxiv.org/pdf/astro-ph/0002230">pdf</a>, <a href="https://arxiv.org/ps/astro-ph/0002230">ps</a>, <a href="https://arxiv.org/format/astro-ph/0002230">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1051/aas:2000339">10.1051/aas:2000339 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Atomic data from the Iron Project.XLIII. Transition probabilities for Fe V </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Nahar%2C+S+N">Sultana N. Nahar</a>, <a href="/search/physics?searchtype=author&query=Delahaye%2C+F">Franck Delahaye</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">Anil K. Pradhan</a>, <a href="/search/physics?searchtype=author&query=Zeippen%2C+C+J">C. J. Zeippen</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="astro-ph/0002230v1-abstract-short" style="display: inline;"> An extensive set of dipole-allowed, intercombination, and forbidden transition probabilities for Fe V is presented. The Breit-Pauli R-matrix (BPRM) method is used to calculate 1.46 x 10^6 oscillator strengths for the allowed and intercombination E1 transitions among 3,865 fine-structure levels dominated by configuration complexes with n <= 10 and l <= 9. These data are complemented by an atomic… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0002230v1-abstract-full').style.display = 'inline'; document.getElementById('astro-ph/0002230v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="astro-ph/0002230v1-abstract-full" style="display: none;"> An extensive set of dipole-allowed, intercombination, and forbidden transition probabilities for Fe V is presented. The Breit-Pauli R-matrix (BPRM) method is used to calculate 1.46 x 10^6 oscillator strengths for the allowed and intercombination E1 transitions among 3,865 fine-structure levels dominated by configuration complexes with n <= 10 and l <= 9. These data are complemented by an atomic structure configuration interaction (CI) calculation using the SUPERSTRUCTURE program for 362 relativistic quadrupole (E2) and magnetic dipole (M1) transitions among 65 low-lying levels dominated by the 3d^4 and 3d^ 4s configurations. Procedures have been developed for the identification of the large number of fine-structure levels and transitions obtained through the BPRM calculations. The target ion Fe VI is represented by an eigenfunction expansion of 19 fine-structure levels of 3d^3 and a set of correlation configurations. Fe V bound levels are obtained with angular and spin symmetries SLπand Jπof the (e + Fe VI) system such that 2S+1 = 5,3,1, L <= 10, J <= 8 of even and odd parities. The completeness of the calculated dataset is verified in terms of all possible bound levels belonging to relevant LS terms and transitions in correspondence with the LS terms. The fine-structure averaged relativistic values are compared with previous Opacity Project LS coupling data and other works. The 362 forbidden transition probabilities considerably extend the available data for the E2 and M1 transtions, and are in good agreement with those computed by Garstang for the 3d^4 transitions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/0002230v1-abstract-full').style.display = 'none'; document.getElementById('astro-ph/0002230v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 10 February, 2000; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2000. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">19 pages, 1 figure. This paper marks the beginning of a large-scale effort of ab initio atomic calculations that should eventually lead to re-calculation of accurate iron opacities. Astron. Astrophys. Suppl. Ser. (in press)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/physics/0001045">arXiv:physics/0001045</a> <span> [<a href="https://arxiv.org/pdf/physics/0001045">pdf</a>, <a href="https://arxiv.org/ps/physics/0001045">ps</a>, <a href="https://arxiv.org/format/physics/0001045">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Space Physics">physics.space-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1238/Physica.Regular.061a00675">10.1238/Physica.Regular.061a00675 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Large-scale Breit-Pauli R-matrix calculations for transition probabilities of Fe V </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Nahar%2C+S+N">Sultana N. Nahar</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">Anil K. Pradhan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="physics/0001045v1-abstract-short" style="display: inline;"> Ab initio theoretical calculations are reported for the electric (E1) dipole allowed and intercombination fine structure transitions in Fe V using the Breit-Pauli R-matrix (BPRM) method. We obtain 3865 bound fine structure levels of Fe V and $1.46 x 10^6$ oscillator strengths, Einstein A-coefficients and line strengths. In addition to the relativistic effects, the intermediate coupling calculati… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('physics/0001045v1-abstract-full').style.display = 'inline'; document.getElementById('physics/0001045v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="physics/0001045v1-abstract-full" style="display: none;"> Ab initio theoretical calculations are reported for the electric (E1) dipole allowed and intercombination fine structure transitions in Fe V using the Breit-Pauli R-matrix (BPRM) method. We obtain 3865 bound fine structure levels of Fe V and $1.46 x 10^6$ oscillator strengths, Einstein A-coefficients and line strengths. In addition to the relativistic effects, the intermediate coupling calculations include extensive electron correlation effects that represent the complex configuration interaction (CI). Fe V bound levels are obtained with angular and spin symmetries $SLπ$ and $Jπ$ of the (e + Fe VI) system such that $2S+1$ = 5,3,1, $L \leq$ 10, $J \leq 8$. The bound levels are obtained as solutions of the Breit-Pauli (e + ion) Hamiltonian for each $Jπ$, and are designated according to the `collision' channel quantum numbers. A major task has been the identification of these large number of bound fine structure levels in terms of standard spectroscopic designations. A new scheme, based on the analysis of quantum defects and channel wavefunctions, has been developed. The identification scheme aims particularly to determine the completeness of the results in terms of all possible bound levels for applications to analysis of experimental measurements and plasma modeling. An uncertainty of 10-20% for most transitions is estimated. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('physics/0001045v1-abstract-full').style.display = 'none'; document.getElementById('physics/0001045v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 January, 2000; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2000. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">31 pages, 1 figure, Physica Scripta (in press)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/astro-ph/9910374">arXiv:astro-ph/9910374</a> <span> [<a href="https://arxiv.org/pdf/astro-ph/9910374">pdf</a>, <a href="https://arxiv.org/ps/astro-ph/9910374">ps</a>, <a href="https://arxiv.org/format/astro-ph/9910374">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Astrophysics">astro-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevA.60.R4221">10.1103/PhysRevA.60.R4221 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Photoionization of Fe XV </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Haque%2C+N">Nasreen Haque</a>, <a href="/search/physics?searchtype=author&query=Pradhan%2C+A+K">Anil K. Pradhan</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="astro-ph/9910374v1-abstract-short" style="display: inline;"> Relativistic and resonance effects in the photoionization of Mg-like Fe~XV are investigated using the Breit-Pauli R-matrix Method (BPRM) at near-threshold and intermediate energies, complemented by the Relativistic Random Phase Approximation (RRPA) and multi-channel quantum defect theory in the energy region up to the L-shell ionization thresholds. The cross sections exhibit extensive resonance… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/9910374v1-abstract-full').style.display = 'inline'; document.getElementById('astro-ph/9910374v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="astro-ph/9910374v1-abstract-full" style="display: none;"> Relativistic and resonance effects in the photoionization of Mg-like Fe~XV are investigated using the Breit-Pauli R-matrix Method (BPRM) at near-threshold and intermediate energies, complemented by the Relativistic Random Phase Approximation (RRPA) and multi-channel quantum defect theory in the energy region up to the L-shell ionization thresholds. The cross sections exhibit extensive resonance structures that considerably enhance the effective photoionization of Fe~XV. These results should be of general interest in photoionization modeling of X-ray sources observed by space observatories. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('astro-ph/9910374v1-abstract-full').style.display = 'none'; document.getElementById('astro-ph/9910374v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 October, 1999; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 1999. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">4 pages, 4 figs., Phys. Rev. A (Rapid Communications, In Press), X-ray Photoionization, Inner-shell Resonant Processes</span> </p> </li> </ol> <nav class="pagination is-small is-centered breathe-horizontal" role="navigation" aria-label="pagination"> <a href="" class="pagination-previous is-invisible">Previous </a> <a href="/search/?searchtype=author&query=Pradhan%2C+K&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Pradhan%2C+K&start=0" class="pagination-link is-current" aria-label="Goto page 1">1 </a> </li> <li> <a href="/search/?searchtype=author&query=Pradhan%2C+K&start=50" class="pagination-link " aria-label="Page 2" aria-current="page">2 </a> </li> </ul> </nav> <div class="is-hidden-tablet">  <span class="help" style="display: inline-block;"><a href="https://github.com/arXiv/arxiv-search/releases">Search v0.5.6 released 2020-02-24</a>  </span> </div> </div> </main> <footer> <div class="columns is-desktop" role="navigation" 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