Search | arXiv e-print repository

<!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8"/> <meta name="viewport" content="width=device-width, initial-scale=1"/>  <link rel="apple-touch-icon" sizes="180x180" href="https://static.arxiv.org/static/base/1.0.0a5/images/icons/apple-touch-icon.png"> <link rel="icon" type="image/png" sizes="32x32" href="https://static.arxiv.org/static/base/1.0.0a5/images/icons/favicon-32x32.png"> <link rel="icon" type="image/png" sizes="16x16" href="https://static.arxiv.org/static/base/1.0.0a5/images/icons/favicon-16x16.png"> <link rel="manifest" href="https://static.arxiv.org/static/base/1.0.0a5/images/icons/site.webmanifest"> <link rel="mask-icon" href="https://static.arxiv.org/static/base/1.0.0a5/images/icons/safari-pinned-tab.svg" color="#b31b1b"> <link rel="shortcut icon" href="https://static.arxiv.org/static/base/1.0.0a5/images/icons/favicon.ico"> <meta name="msapplication-TileColor" content="#b31b1b"> <meta name="msapplication-config" content="images/icons/browserconfig.xml"> <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 src="https://static.arxiv.org/static/base/1.0.0a5/js/notification.js"></script> <link rel="stylesheet" href="https://static.arxiv.org/static/search/0.5.6/css/bulma-tooltip.min.css" /> <link rel="stylesheet" href="https://static.arxiv.org/static/search/0.5.6/css/search.css" /> <script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha256-k2WSCIexGzOj3Euiig+TlR8gA0EmPjuc79OEeY5L45g=" crossorigin="anonymous"></script> <script src="https://static.arxiv.org/static/search/0.5.6/js/fieldset.js"></script> <style> radio#cf-customfield_11400 { display: none; } </style> </head> <body> <header><a href="#main-container" class="is-sr-only">Skip to main content</a>  <div class="attribution level is-marginless" role="banner"> <div class="level-left"> <a class="level-item" href="https://cornell.edu/"><img src="https://static.arxiv.org/static/base/1.0.0a5/images/cornell-reduced-white-SMALL.svg" alt="Cornell University" width="200" aria-label="logo" /></a> </div> <div class="level-right is-marginless"><p class="sponsors level-item is-marginless"><span id="support-ack-url">We gratefully acknowledge support from<br /> the Simons Foundation, <a href="https://info.arxiv.org/about/ourmembers.html">member institutions</a>, and all contributors. <a href="https://info.arxiv.org/about/donate.html">Donate</a></span></p></div> </div>  <div class="identity level is-marginless"> <div class="level-left"> <div class="level-item"> <a class="arxiv" href="https://arxiv.org/" aria-label="arxiv-logo"> <img src="https://static.arxiv.org/static/base/1.0.0a5/images/arxiv-logo-one-color-white.svg" aria-label="logo" alt="arxiv logo" width="85" style="width:85px;"/> </a> </div> </div> <div class="search-block level-right"> <form class="level-item mini-search" method="GET" action="https://arxiv.org/search"> <div class="field has-addons"> <div class="control"> <input class="input is-small" type="text" name="query" placeholder="Search..." aria-label="Search term or terms" /> <p class="help"><a href="https://info.arxiv.org/help">Help</a> | <a href="https://arxiv.org/search/advanced">Advanced Search</a></p> </div> <div class="control"> <div class="select is-small"> <select name="searchtype" aria-label="Field to search"> <option value="all" selected="selected">All fields</option> <option value="title">Title</option> <option value="author">Author</option> <option value="abstract">Abstract</option> <option value="comments">Comments</option> <option value="journal_ref">Journal reference</option> <option value="acm_class">ACM classification</option> <option value="msc_class">MSC classification</option> <option value="report_num">Report number</option> <option value="paper_id">arXiv identifier</option> <option value="doi">DOI</option> <option value="orcid">ORCID</option> <option value="author_id">arXiv author ID</option> <option value="help">Help pages</option> <option value="full_text">Full text</option> </select> </div> </div> <input type="hidden" name="source" value="header"> <button class="button is-small is-cul-darker">Search</button> </div> </form> </div> </div>  <div class="container"> <div class="user-tools is-size-7 has-text-right has-text-weight-bold" role="navigation" aria-label="User menu"> <a href="https://arxiv.org/login">Login</a> </div> </div> </header> <main class="container" id="main-container"> <div class="level is-marginless"> <div class="level-left"> <h1 class="title is-clearfix"> Showing 1–29 of 29 results for author: <span class="mathjax">Coffee, R</span> </h1> </div> <div class="level-right is-hidden-mobile">  <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> <div class="content"> <form method="GET" action="/search/physics" aria-role="search"> Searching in archive <strong>physics</strong>. <a href="/search/?searchtype=author&query=Coffee%2C+R">Search in all archives.</a> <div class="field has-addons-tablet"> <div class="control is-expanded"> <label for="query" class="hidden-label">Search term or terms</label> <input class="input is-medium" id="query" name="query" placeholder="Search term..." type="text" value="Coffee, R"> </div> <div class="select control is-medium"> <label class="is-hidden" for="searchtype">Field</label> <select class="is-medium" id="searchtype" name="searchtype"><option value="all">All fields</option><option value="title">Title</option><option selected value="author">Author(s)</option><option value="abstract">Abstract</option><option value="comments">Comments</option><option value="journal_ref">Journal reference</option><option value="acm_class">ACM classification</option><option value="msc_class">MSC classification</option><option value="report_num">Report number</option><option value="paper_id">arXiv identifier</option><option value="doi">DOI</option><option value="orcid">ORCID</option><option value="license">License (URI)</option><option value="author_id">arXiv author ID</option><option value="help">Help pages</option><option value="full_text">Full text</option></select> </div> <div class="control"> <button class="button is-link is-medium">Search</button> </div> </div> <div class="field"> <div class="control is-size-7"> <label class="radio"> <input checked id="abstracts-0" name="abstracts" type="radio" value="show"> Show abstracts </label> <label class="radio"> <input id="abstracts-1" name="abstracts" type="radio" value="hide"> Hide abstracts </label> </div> </div> <div class="is-clearfix" style="height: 2.5em"> <div class="is-pulled-right"> <a href="/search/advanced?terms-0-term=Coffee%2C+R&terms-0-field=author&size=50&order=-announced_date_first">Advanced Search</a> </div> </div> <input type="hidden" name="order" value="-announced_date_first"> <input type="hidden" name="size" value="50"> </form> <div class="level breathe-horizontal"> <div class="level-left"> <form method="GET" action="/search/"> <div style="display: none;"> <select id="searchtype" name="searchtype"><option value="all">All fields</option><option value="title">Title</option><option selected value="author">Author(s)</option><option value="abstract">Abstract</option><option value="comments">Comments</option><option value="journal_ref">Journal reference</option><option value="acm_class">ACM classification</option><option value="msc_class">MSC classification</option><option value="report_num">Report number</option><option value="paper_id">arXiv identifier</option><option value="doi">DOI</option><option value="orcid">ORCID</option><option value="license">License (URI)</option><option value="author_id">arXiv author ID</option><option value="help">Help pages</option><option value="full_text">Full text</option></select> <input id="query" name="query" type="text" value="Coffee, R"> <ul id="abstracts"><li><input checked id="abstracts-0" name="abstracts" type="radio" value="show"> <label for="abstracts-0">Show abstracts</label></li><li><input id="abstracts-1" name="abstracts" type="radio" value="hide"> <label for="abstracts-1">Hide abstracts</label></li></ul> </div> <div class="box field is-grouped is-grouped-multiline level-item"> <div class="control"> <span class="select is-small"> <select id="size" name="size"><option value="25">25</option><option selected value="50">50</option><option value="100">100</option><option value="200">200</option></select> </span> <label for="size">results per page</label>. </div> <div class="control"> <label for="order">Sort results by</label> <span class="select is-small"> <select id="order" name="order"><option selected value="-announced_date_first">Announcement date (newest first)</option><option value="announced_date_first">Announcement date (oldest first)</option><option value="-submitted_date">Submission date (newest first)</option><option value="submitted_date">Submission date (oldest first)</option><option value="">Relevance</option></select> </span> </div> <div class="control"> <button class="button is-small is-link">Go</button> </div> </div> </form> </div> </div> <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/2502.16141">arXiv:2502.16141</a> <span> [<a href="https://arxiv.org/pdf/2502.16141">pdf</a>, <a href="https://arxiv.org/format/2502.16141">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="Accelerator Physics">physics.acc-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Data Analysis, Statistics and Probability">physics.data-an</span> </div> </div> <p class="title is-5 mathjax"> A Hybrid Neural Network for High-Throughput Attosecond Resolution Single-shot X-ray Pulse Characterization </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Hirschman%2C+J">Jack Hirschman</a>, <a href="/search/physics?searchtype=author&query=Mencer%2C+B">Benjamin Mencer</a>, <a href="/search/physics?searchtype=author&query=Obaid%2C+R">Razib Obaid</a>, <a href="/search/physics?searchtype=author&query=Shackelford%2C+A">Amanda Shackelford</a>, <a href="/search/physics?searchtype=author&query=Coffee%2C+R">Ryan Coffee</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="2502.16141v1-abstract-short" style="display: inline;"> As scientific facilities transition toward high-throughput, data-intensive experiments, there is a growing need for real-time computing at the edge to support autonomous decision-making and minimize data transmission bottlenecks. Department of Energy (DOE) initiatives emphasize the development of heterogeneous computing architectures that integrate machine learning (ML) models with specialized har… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2502.16141v1-abstract-full').style.display = 'inline'; document.getElementById('2502.16141v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2502.16141v1-abstract-full" style="display: none;"> As scientific facilities transition toward high-throughput, data-intensive experiments, there is a growing need for real-time computing at the edge to support autonomous decision-making and minimize data transmission bottlenecks. Department of Energy (DOE) initiatives emphasize the development of heterogeneous computing architectures that integrate machine learning (ML) models with specialized hardware such as FPGAs, GPUs, and embedded systems to meet the demands of next-generation experiments. These advances are critical for facilities such as X-ray free-electron lasers (XFELs), where high-repetition-rate experiments produce terabyte-scale datasets, requiring real-time analysis and control. To address this challenge, we introduce DCIFR, a deep learning framework optimized for edge processing and high-speed X-ray diagnostics at SLAC's Linac Coherent Light Source (LCLS). DCIFR leverages a hybrid neural architecture, combining convolutional neural networks (CNNs), bidirectional long short-term memory (BiLSTM) networks, and residual neural networks (ResNets) to denoise sinograms, classify X-ray sub-spikes, and extract phase separation with attosecond precision. The model achieves a phase extraction accuracy of 0.04652 radians (29.6 attoseconds at 1.2 um streaking wavelength) with inference latencies of 168.3 us and throughput exceeding 10kHz. Designed for deployment on heterogeneous architectures, DCIFR reduces computational overhead and supports future AI-driven feedback loops for ultrafast experiments. This work demonstrates the potential of edge AI and hardware acceleration to drive scalable, autonomous data analysis in next-generation DOE scientific facilities. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2502.16141v1-abstract-full').style.display = 'none'; document.getElementById('2502.16141v1-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 February, 2025; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2025. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2305.19455">arXiv:2305.19455</a> <span> [<a href="https://arxiv.org/pdf/2305.19455">pdf</a>, <a href="https://arxiv.org/format/2305.19455">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Artificial Intelligence">cs.AI</span> </div> </div> <p class="title is-5 mathjax"> Implementation of a framework for deploying AI inference engines in FPGAs </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Herbst%2C+R">Ryan Herbst</a>, <a href="/search/physics?searchtype=author&query=Coffee%2C+R">Ryan Coffee</a>, <a href="/search/physics?searchtype=author&query=Fronk%2C+N">Nathan Fronk</a>, <a href="/search/physics?searchtype=author&query=Kim%2C+K">Kukhee Kim</a>, <a href="/search/physics?searchtype=author&query=Kim%2C+K">Kuktae Kim</a>, <a href="/search/physics?searchtype=author&query=Ruckman%2C+L">Larry Ruckman</a>, <a href="/search/physics?searchtype=author&query=Russell%2C+J+J">J. J. Russell</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="2305.19455v1-abstract-short" style="display: inline;"> The LCLS2 Free Electron Laser FEL will generate xray pulses to beamline experiments at up to 1Mhz These experimentals will require new ultrahigh rate UHR detectors that can operate at rates above 100 kHz and generate data throughputs upwards of 1 TBs a data velocity which requires prohibitively large investments in storage infrastructure Machine Learning has demonstrated the potential to digest la… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.19455v1-abstract-full').style.display = 'inline'; document.getElementById('2305.19455v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2305.19455v1-abstract-full" style="display: none;"> The LCLS2 Free Electron Laser FEL will generate xray pulses to beamline experiments at up to 1Mhz These experimentals will require new ultrahigh rate UHR detectors that can operate at rates above 100 kHz and generate data throughputs upwards of 1 TBs a data velocity which requires prohibitively large investments in storage infrastructure Machine Learning has demonstrated the potential to digest large datasets to extract relevant insights however current implementations show latencies that are too high for realtime data reduction objectives SLAC has endeavored on the creation of a software framework which translates MLs structures for deployment on Field Programmable Gate Arrays FPGAs deployed at the Edge of the data chain close to the instrumentation This framework leverages Xilinxs HLS framework presenting an API modeled after the open source Keras interface to the TensorFlow library This SLAC Neural Network Library SNL framework is designed with a streaming data approach optimizing the data flow between layers while minimizing the buffer data buffering requirements The goal is to ensure the highest possible framerate while keeping the maximum latency constrained to the needs of the experiment Our framework is designed to ensure the RTL implementation of the network layers supporting full redeployment of weights and biases without requiring resynthesis after training The ability to reduce the precision of the implemented networks through quantization is necessary to optimize the use of both DSP and memory resources in the FPGA We currently have a preliminary version of the toolset and are experimenting with both general purpose example networks and networks being designed for specific LCLS2 experiments. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.19455v1-abstract-full').style.display = 'none'; document.getElementById('2305.19455v1-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> 30 May, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 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, 1 figure 2 tables</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2212.08745">arXiv:2212.08745</a> <span> [<a href="https://arxiv.org/pdf/2212.08745">pdf</a>, <a href="https://arxiv.org/format/2212.08745">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Plasma Physics">physics.plasm-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Data Analysis, Statistics and Probability">physics.data-an</span> </div> </div> <p class="title is-5 mathjax"> Automatic Identification of Edge Localized Modes in the DIII-D Tokamak </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=O%27Shea%2C+F+H">Finn H. O'Shea</a>, <a href="/search/physics?searchtype=author&query=Joung%2C+S">Semin Joung</a>, <a href="/search/physics?searchtype=author&query=Smith%2C+D+R">David R. Smith</a>, <a href="/search/physics?searchtype=author&query=Coffee%2C+R">Ryan Coffee</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="2212.08745v1-abstract-short" style="display: inline;"> Fusion power production in tokamaks uses discharge configurations that risk producing strong Type I Edge Localized Modes. The largest of these modes will likely increase impurities in the plasma and potentially damage plasma facing components such as the protective heat and waste divertor. Machine learning-based prediction and control may provide for online mitigation of these damaging modes befor… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.08745v1-abstract-full').style.display = 'inline'; document.getElementById('2212.08745v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2212.08745v1-abstract-full" style="display: none;"> Fusion power production in tokamaks uses discharge configurations that risk producing strong Type I Edge Localized Modes. The largest of these modes will likely increase impurities in the plasma and potentially damage plasma facing components such as the protective heat and waste divertor. Machine learning-based prediction and control may provide for online mitigation of these damaging modes before they grow too large to suppress. To that end, large labeled datasets are required for supervised training of machine learning models. We present an algorithm that achieves 97.7% precision when automatically labeling Edge Localized Modes in the large DIII-D tokamak discharge database. The algorithm has no user controlled parameters and is largely robust to tokamak and plasma configuration changes. This automatically-labeled database of events can subsequently feed future training of machine learning models aimed at autonomous Edge Localized Mode control and suppression. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.08745v1-abstract-full').style.display = 'none'; document.getElementById('2212.08745v1-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, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 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">7 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/2209.05233">arXiv:2209.05233</a> <span> [<a href="https://arxiv.org/pdf/2209.05233">pdf</a>, <a href="https://arxiv.org/format/2209.05233">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Data Analysis, Statistics and Probability">physics.data-an</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/10.1007/978-3-031-23606-8_7">10.1007/978-3-031-23606-8_7 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> At-the-edge Data Processing for Low Latency High Throughput Machine Learning Algorithms </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Hirschman%2C+J">Jack Hirschman</a>, <a href="/search/physics?searchtype=author&query=Kamalov%2C+A">Andrei Kamalov</a>, <a href="/search/physics?searchtype=author&query=Obaid%2C+R">Razib Obaid</a>, <a href="/search/physics?searchtype=author&query=O%27Shea%2C+F+H">Finn H. O'Shea</a>, <a href="/search/physics?searchtype=author&query=Coffee%2C+R+N">Ryan N Coffee</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="2209.05233v1-abstract-short" style="display: inline;"> High throughput and low latency data processing is essential for systems requiring live decision making, control, and machine learning-optimized data reduction. We focus on two distinct use cases for in-flight streaming data processing for a) X-ray pulse reconstruction at SLAC's LCLS-II Free-Electron Laser and b) control diagnostics at the DIII-D tokamak fusion reactor. Both cases exemplify high t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.05233v1-abstract-full').style.display = 'inline'; document.getElementById('2209.05233v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2209.05233v1-abstract-full" style="display: none;"> High throughput and low latency data processing is essential for systems requiring live decision making, control, and machine learning-optimized data reduction. We focus on two distinct use cases for in-flight streaming data processing for a) X-ray pulse reconstruction at SLAC's LCLS-II Free-Electron Laser and b) control diagnostics at the DIII-D tokamak fusion reactor. Both cases exemplify high throughput and low latency control feedback and motivate our focus on machine learning at the edge where data processing and machine learning algorithms can be implemented in field programmable gate array based hardware immediately after the diagnostic sensors. We present our recent work on a data preprocessing chain which requires fast featurization for information encoding. We discuss several options for such algorithms with the primary focus on our discrete cosine and sine transform-based approach adapted for streaming data. These algorithms are primarily aimed at implementation in field programmable gate arrays, favoring linear algebra operations that are also aligned with the recent advances in inference accelerators for the computational edge. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.05233v1-abstract-full').style.display = 'none'; document.getElementById('2209.05233v1-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 September, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 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">18 pages, 7 figures; To be published in Smoky Mountains Computational Sciences and Engineering Conference 2022 (SMC 2022) proceedings</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2208.11250">arXiv:2208.11250</a> <span> [<a href="https://arxiv.org/pdf/2208.11250">pdf</a>, <a href="https://arxiv.org/ps/2208.11250">ps</a>, <a href="https://arxiv.org/format/2208.11250">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> </div> </div> <p class="title is-5 mathjax"> An Online Dynamic Amplitude-Correcting Gradient Estimation Technique to Align X-ray Focusing Optics </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Breckling%2C+S">Sean Breckling</a>, <a href="/search/physics?searchtype=author&query=Dresselhaus-Marais%2C+L+E">Leora E. Dresselhaus-Marais</a>, <a href="/search/physics?searchtype=author&query=Machorro%2C+E">Eric Machorro</a>, <a href="/search/physics?searchtype=author&query=Brennan%2C+M+C">Michael C. Brennan</a>, <a href="/search/physics?searchtype=author&query=Pillow%2C+J">Jordan Pillow</a>, <a href="/search/physics?searchtype=author&query=Espanol%2C+M">Malena Espanol</a>, <a href="/search/physics?searchtype=author&query=Kozioziemski%2C+B">Bernard Kozioziemski</a>, <a href="/search/physics?searchtype=author&query=Coffee%2C+R">Ryan Coffee</a>, <a href="/search/physics?searchtype=author&query=Kim%2C+S">Sunam Kim</a>, <a href="/search/physics?searchtype=author&query=Kim%2C+S">Sangsoo Kim</a>, <a href="/search/physics?searchtype=author&query=Nam%2C+D">Daewoong Nam</a>, <a href="/search/physics?searchtype=author&query=Gonzales%2C+A">Arnulfo Gonzales</a>, <a href="/search/physics?searchtype=author&query=Lund%2C+M">Margaret Lund</a>, <a href="/search/physics?searchtype=author&query=Adams%2C+J">Jesse Adams</a>, <a href="/search/physics?searchtype=author&query=Champion%2C+D">Daniel Champion</a>, <a href="/search/physics?searchtype=author&query=Williams%2C+A">Ajanae Williams</a>, <a href="/search/physics?searchtype=author&query=Joyce%2C+K">Kevin Joyce</a>, <a href="/search/physics?searchtype=author&query=Howard%2C+M">Marylesa Howard</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="2208.11250v2-abstract-short" style="display: inline;"> High-brightness X-ray pulses, as generated at synchrotrons and X-ray free electron lasers (XFEL), are used in a variety of scientific experiments. Many experimental testbeds require optical equipment, e.g Compound Refractive Lenses (CRLs), to be precisely aligned and focused. The lateral alignment of CRLs to a beamline requires precise positioning along four axes: two translational, and the two ro… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.11250v2-abstract-full').style.display = 'inline'; document.getElementById('2208.11250v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2208.11250v2-abstract-full" style="display: none;"> High-brightness X-ray pulses, as generated at synchrotrons and X-ray free electron lasers (XFEL), are used in a variety of scientific experiments. Many experimental testbeds require optical equipment, e.g Compound Refractive Lenses (CRLs), to be precisely aligned and focused. The lateral alignment of CRLs to a beamline requires precise positioning along four axes: two translational, and the two rotational. At a synchrotron, alignment is often accomplished manually. However, XFEL beamlines present a beam brightness that fluctuates in time, making manual alignment a time-consuming endeavor. Automation using classic stochastic methods often fail, given the errant gradient estimates. We present an online correction based on the combination of a generalized finite difference stencil and a time-dependent sampling pattern. Error expectation is analyzed, and efficacy is demonstrated. We provide a proof of concept by laterally aligning optics on a simulated XFEL beamline. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.11250v2-abstract-full').style.display = 'none'; document.getElementById('2208.11250v2-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> 30 September, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 23 August, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2022. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2207.09600">arXiv:2207.09600</a> <span> [<a href="https://arxiv.org/pdf/2207.09600">pdf</a>, <a href="https://arxiv.org/ps/2207.09600">ps</a>, <a href="https://arxiv.org/format/2207.09600">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="Chemical Physics">physics.chem-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/10.1038/s42005-023-01420-9">10.1038/s42005-023-01420-9 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Applying Bayesian Inference and deterministic anisotropy to retrieve the molecular structure $|唯(\boldsymbol{R})|^2$ distribution from gas-phase diffraction experiments </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Hegazy%2C+K">Kareem Hegazy</a>, <a href="/search/physics?searchtype=author&query=Makhija%2C+V">Varun Makhija</a>, <a href="/search/physics?searchtype=author&query=Bucksbaum%2C+P">Phil Bucksbaum</a>, <a href="/search/physics?searchtype=author&query=Corbett%2C+J">Jeff Corbett</a>, <a href="/search/physics?searchtype=author&query=Cryan%2C+J">James Cryan</a>, <a href="/search/physics?searchtype=author&query=Hartmann%2C+N">Nick Hartmann</a>, <a href="/search/physics?searchtype=author&query=Ilchen%2C+M">Markus Ilchen</a>, <a href="/search/physics?searchtype=author&query=Jobe%2C+K">Keith Jobe</a>, <a href="/search/physics?searchtype=author&query=Li%2C+R">Renkai Li</a>, <a href="/search/physics?searchtype=author&query=Makasyuk%2C+I">Igor Makasyuk</a>, <a href="/search/physics?searchtype=author&query=Shen%2C+X">Xiaozhe Shen</a>, <a href="/search/physics?searchtype=author&query=Wang%2C+X">Xijie Wang</a>, <a href="/search/physics?searchtype=author&query=Weathersby%2C+S">Stephen Weathersby</a>, <a href="/search/physics?searchtype=author&query=Yang%2C+J">Jie Yang</a>, <a href="/search/physics?searchtype=author&query=Coffee%2C+R">Ryan Coffee</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="2207.09600v3-abstract-short" style="display: inline;"> Currently, our general approach to retrieving molecular structures from ultrafast gas-phase diffraction heavily relies on complex ab initio electronic or vibrational excited state simulations to make conclusive interpretations. Without such simulations, inverting this measurement for the structural probability distribution is typically intractable. This creates a so-called inverse problem. In this… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.09600v3-abstract-full').style.display = 'inline'; document.getElementById('2207.09600v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2207.09600v3-abstract-full" style="display: none;"> Currently, our general approach to retrieving molecular structures from ultrafast gas-phase diffraction heavily relies on complex ab initio electronic or vibrational excited state simulations to make conclusive interpretations. Without such simulations, inverting this measurement for the structural probability distribution is typically intractable. This creates a so-called inverse problem. In this work, we develop a broadly applicable method that addresses this inverse problem by approximating the molecular frame structure $|唯(\boldsymbol{R}, t)|^2$ distribution independent of these complex simulations. We retrieve the vibronic ground state $|唯(\boldsymbol{R})|^2$ for both simulated stretched NO$_2$ and measured N$_2$O. From measured N$_2$O, we observe 40 mAngstroms coordinate-space resolution from 3.75 inverse Angstroms reciprocal space range and poor signal-to-noise, a 50X improvement over traditional Fourier transform methods. In simulated NO$_2$, typical to high signal-to-noise levels predict 100--1000X resolution improvements, down to 0.1 mAngstroms. By directly measuring the width of $|唯(\boldsymbol{R})|^2$, we open ultrafast gas-phase diffraction capabilities to measurements beyond current analysis approaches. This method has the potential to effectively turn gas-phase ultrafast diffraction into a discovery-oriented technique to probe systems that are prohibitively difficult to simulate. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.09600v3-abstract-full').style.display = 'none'; document.getElementById('2207.09600v3-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 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 19 July, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 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">16 pages, 8 figures, 2 tables. Please find the analysis code and templates for new molecules at https://github.com/khegazy/BIGR</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Nature Commun Phys 6, 325 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2109.09815">arXiv:2109.09815</a> <span> [<a href="https://arxiv.org/pdf/2109.09815">pdf</a>, <a href="https://arxiv.org/format/2109.09815">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Plasma Physics">physics.plasm-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/10.1088/1367-2630/ac5e86">10.1088/1367-2630/ac5e86 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Few-femtosecond resolved imaging of laser-driven nanoplasma expansion </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Peltz%2C+C">C. Peltz</a>, <a href="/search/physics?searchtype=author&query=Powell%2C+J+A">J. A. Powell</a>, <a href="/search/physics?searchtype=author&query=Rupp%2C+P">P. Rupp</a>, <a href="/search/physics?searchtype=author&query=Summers%2C+A">A Summers</a>, <a href="/search/physics?searchtype=author&query=Gorkhover%2C+T">T. Gorkhover</a>, <a href="/search/physics?searchtype=author&query=Gallei%2C+M">M. Gallei</a>, <a href="/search/physics?searchtype=author&query=Halfpap%2C+I">I. Halfpap</a>, <a href="/search/physics?searchtype=author&query=Antonsson%2C+E">E. Antonsson</a>, <a href="/search/physics?searchtype=author&query=Langer%2C+B">B. Langer</a>, <a href="/search/physics?searchtype=author&query=Trallero-Herrero%2C+C">C. Trallero-Herrero</a>, <a href="/search/physics?searchtype=author&query=Graf%2C+C">C. Graf</a>, <a href="/search/physics?searchtype=author&query=Ray%2C+D">D. Ray</a>, <a href="/search/physics?searchtype=author&query=Liu%2C+Q">Q. Liu</a>, <a href="/search/physics?searchtype=author&query=Osipov%2C+T">T. Osipov</a>, <a href="/search/physics?searchtype=author&query=Bucher%2C+M">M. Bucher</a>, <a href="/search/physics?searchtype=author&query=Ferguson%2C+K">K. Ferguson</a>, <a href="/search/physics?searchtype=author&query=M%C3%B6ller%2C+S">S. M枚ller</a>, <a href="/search/physics?searchtype=author&query=Zherebtsov%2C+S">S. Zherebtsov</a>, <a href="/search/physics?searchtype=author&query=Rolles%2C+D">D. Rolles</a>, <a href="/search/physics?searchtype=author&query=R%C3%BChl%2C+E">E. R眉hl</a>, <a href="/search/physics?searchtype=author&query=Coslovich%2C+G">G. Coslovich</a>, <a href="/search/physics?searchtype=author&query=Coffee%2C+R+N">R. N. Coffee</a>, <a href="/search/physics?searchtype=author&query=Bostedt%2C+C">C. Bostedt</a>, <a href="/search/physics?searchtype=author&query=Rudenko%2C+A">A. Rudenko</a>, <a href="/search/physics?searchtype=author&query=Kling%2C+M+F">M. F. Kling</a> , et al. (1 additional authors not shown) </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="2109.09815v2-abstract-short" style="display: inline;"> The free expansion of a planar plasma surface is a fundamental non-equilibrium process relevant for various fields but as-yet experimentally still difficult to capture. The significance of the associated spatiotemporal plasma motion ranges from astrophysics and controlled fusion to laser machining, surface high-harmonic generation, plasma mirrors, and laser-particle acceleration. Here, we show tha… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.09815v2-abstract-full').style.display = 'inline'; document.getElementById('2109.09815v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2109.09815v2-abstract-full" style="display: none;"> The free expansion of a planar plasma surface is a fundamental non-equilibrium process relevant for various fields but as-yet experimentally still difficult to capture. The significance of the associated spatiotemporal plasma motion ranges from astrophysics and controlled fusion to laser machining, surface high-harmonic generation, plasma mirrors, and laser-particle acceleration. Here, we show that x-ray coherent diffractive imaging can surpass existing approaches and enables the quantitative real-time analysis of the sudden free expansion of nanoplasmas. For laser-ionized SiO$_2$ nanospheres, we resolve the formation of the emerging nearly self-similar plasma profile evolution and expose the so far inaccessible shell-wise expansion dynamics including the associated startup delay and rarefaction front velocity. Our results establish time-resolved diffractive imaging as an accurate quantitative diagnostic platform for tracing and characterizing plasma expansion and indicate the possibility to resolve various laser-driven processes including shock formation and wave-breaking phenomena with unprecedented resolution. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.09815v2-abstract-full').style.display = 'none'; document.getElementById('2109.09815v2-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 March, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 20 September, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2021. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2105.08854">arXiv:2105.08854</a> <span> [<a href="https://arxiv.org/pdf/2105.08854">pdf</a>, <a href="https://arxiv.org/format/2105.08854">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Chemical Physics">physics.chem-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/10.1126/science.abj2096">10.1126/science.abj2096 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Attosecond Coherent Electron Motion in Auger-Meitner Decay </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Li%2C+S">Siqi Li</a>, <a href="/search/physics?searchtype=author&query=Driver%2C+T">Taran Driver</a>, <a href="/search/physics?searchtype=author&query=Rosenberger%2C+P">Philipp Rosenberger</a>, <a href="/search/physics?searchtype=author&query=Champenois%2C+E+G">Elio G. Champenois</a>, <a href="/search/physics?searchtype=author&query=Duris%2C+J">Joseph Duris</a>, <a href="/search/physics?searchtype=author&query=Al-Haddad%2C+A">Andre Al-Haddad</a>, <a href="/search/physics?searchtype=author&query=Averbukh%2C+V">Vitali Averbukh</a>, <a href="/search/physics?searchtype=author&query=Barnard%2C+J+C+T">Jonathan C. T. Barnard</a>, <a href="/search/physics?searchtype=author&query=Berrah%2C+N">Nora Berrah</a>, <a href="/search/physics?searchtype=author&query=Bostedt%2C+C">Christoph Bostedt</a>, <a href="/search/physics?searchtype=author&query=Bucksbaum%2C+P+H">Philip H. Bucksbaum</a>, <a href="/search/physics?searchtype=author&query=Coffee%2C+R">Ryan Coffee</a>, <a href="/search/physics?searchtype=author&query=DiMauro%2C+L+F">Louis F. DiMauro</a>, <a href="/search/physics?searchtype=author&query=Fang%2C+L">Li Fang</a>, <a href="/search/physics?searchtype=author&query=Garratt%2C+D">Douglas Garratt</a>, <a href="/search/physics?searchtype=author&query=Gatton%2C+A">Averell Gatton</a>, <a href="/search/physics?searchtype=author&query=Guo%2C+Z">Zhaoheng Guo</a>, <a href="/search/physics?searchtype=author&query=Hartmann%2C+G">Gregor Hartmann</a>, <a href="/search/physics?searchtype=author&query=Haxton%2C+D">Daniel Haxton</a>, <a href="/search/physics?searchtype=author&query=Helml%2C+W">Wolfram Helml</a>, <a href="/search/physics?searchtype=author&query=Huang%2C+Z">Zhirong Huang</a>, <a href="/search/physics?searchtype=author&query=LaForge%2C+A+C">Aaron C. LaForge</a>, <a href="/search/physics?searchtype=author&query=Kamalov%2C+A">Andrei Kamalov</a>, <a href="/search/physics?searchtype=author&query=Knurr%2C+J">Jonas Knurr</a>, <a href="/search/physics?searchtype=author&query=Lin%2C+M">Ming-Fu Lin</a> , et al. (16 additional authors not shown) </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="2105.08854v1-abstract-short" style="display: inline;"> In quantum systems, coherent superpositions of electronic states evolve on ultrafast timescales (few femtosecond to attosecond, 1 as = 0.001 fs = 10^{-18} s), leading to a time dependent charge density. Here we exploit the first attosecond soft x-ray pulses produced by an x-ray free-electron laser to induce a coherent core-hole excitation in nitric oxide. Using an additional circularly polarized i… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.08854v1-abstract-full').style.display = 'inline'; document.getElementById('2105.08854v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2105.08854v1-abstract-full" style="display: none;"> In quantum systems, coherent superpositions of electronic states evolve on ultrafast timescales (few femtosecond to attosecond, 1 as = 0.001 fs = 10^{-18} s), leading to a time dependent charge density. Here we exploit the first attosecond soft x-ray pulses produced by an x-ray free-electron laser to induce a coherent core-hole excitation in nitric oxide. Using an additional circularly polarized infrared laser pulse we create a clock to time-resolve the electron dynamics, and demonstrate control of the coherent electron motion by tuning the photon energy of the x-ray pulse. Core-excited states offer a fundamental test bed for studying coherent electron dynamics in highly excited and strongly correlated matter. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.08854v1-abstract-full').style.display = 'none'; document.getElementById('2105.08854v1-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 May, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2021. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2105.06507">arXiv:2105.06507</a> <span> [<a href="https://arxiv.org/pdf/2105.06507">pdf</a>, <a href="https://arxiv.org/format/2105.06507">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Chemical Physics">physics.chem-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-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/PhysRevX.11.031048">10.1103/PhysRevX.11.031048 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Correlation Driven Transient Hole Dynamics Resolved in Space and Time in the Isopropanol Molecule </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Barillot%2C+T">T. Barillot</a>, <a href="/search/physics?searchtype=author&query=Alexander%2C+O">O. Alexander</a>, <a href="/search/physics?searchtype=author&query=Cooper%2C+B">B. Cooper</a>, <a href="/search/physics?searchtype=author&query=Driver%2C+T">T. Driver</a>, <a href="/search/physics?searchtype=author&query=Garratt%2C+D">D. Garratt</a>, <a href="/search/physics?searchtype=author&query=Li%2C+S">S. Li</a>, <a href="/search/physics?searchtype=author&query=Haddad%2C+A+A">A. Al Haddad</a>, <a href="/search/physics?searchtype=author&query=Sanchez-Gonzalez%2C+A">A. Sanchez-Gonzalez</a>, <a href="/search/physics?searchtype=author&query=Ag%C3%A5ker%2C+M">M. Ag氓ker</a>, <a href="/search/physics?searchtype=author&query=Arrell%2C+C">C. Arrell</a>, <a href="/search/physics?searchtype=author&query=Bearpark%2C+M">M. Bearpark</a>, <a href="/search/physics?searchtype=author&query=Berrah%2C+N">N. Berrah</a>, <a href="/search/physics?searchtype=author&query=Bostedt%2C+C">C. Bostedt</a>, <a href="/search/physics?searchtype=author&query=Bozek%2C+J">J. Bozek</a>, <a href="/search/physics?searchtype=author&query=Brahms%2C+C">C. Brahms</a>, <a href="/search/physics?searchtype=author&query=Bucksbaum%2C+P+H">P. H. Bucksbaum</a>, <a href="/search/physics?searchtype=author&query=Clark%2C+A">A. Clark</a>, <a href="/search/physics?searchtype=author&query=Doumy%2C+G">G. Doumy</a>, <a href="/search/physics?searchtype=author&query=Feifel%2C+R">R. Feifel</a>, <a href="/search/physics?searchtype=author&query=Frasinski%2C+L+J">L. J. Frasinski</a>, <a href="/search/physics?searchtype=author&query=Jarosch%2C+S">S. Jarosch</a>, <a href="/search/physics?searchtype=author&query=Johnson%2C+A+S">A. S. Johnson</a>, <a href="/search/physics?searchtype=author&query=Kjellsson%2C+L">L. Kjellsson</a>, <a href="/search/physics?searchtype=author&query=Koloren%C4%8D%2C+P">P. Koloren膷</a>, <a href="/search/physics?searchtype=author&query=Kumagai%2C+Y">Y. Kumagai</a> , et al. (24 additional authors not shown) </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="2105.06507v1-abstract-short" style="display: inline;"> The possibility of suddenly ionized molecules undergoing extremely fast electron hole dynamics prior to significant structural change was first recognized more than 20 years ago and termed charge migration. The accurate probing of ultrafast electron hole dynamics requires measurements that have both sufficient temporal resolution and can detect the localization of a specific hole within the molecu… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.06507v1-abstract-full').style.display = 'inline'; document.getElementById('2105.06507v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2105.06507v1-abstract-full" style="display: none;"> The possibility of suddenly ionized molecules undergoing extremely fast electron hole dynamics prior to significant structural change was first recognized more than 20 years ago and termed charge migration. The accurate probing of ultrafast electron hole dynamics requires measurements that have both sufficient temporal resolution and can detect the localization of a specific hole within the molecule. We report an investigation of the dynamics of inner valence hole states in isopropanol where we use an x-ray pump/x-ray probe experiment, with site and state-specific probing of a transient hole state localized near the oxygen atom in the molecule, together with an ab initio theoretical treatment. We record the signature of transient hole dynamics and make the first observation of dynamics driven by frustrated Auger-Meitner transitions. We verify that the hole lifetime is consistent with our theoretical prediction. This state-specific measurement paves the way to widespread application for observations of transient hole dynamics localized in space and time in molecules and thus to charge transfer phenomena that are fundamental in chemical and material physics. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.06507v1-abstract-full').style.display = 'none'; document.getElementById('2105.06507v1-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, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. X 11, 031048 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2103.07603">arXiv:2103.07603</a> <span> [<a href="https://arxiv.org/pdf/2103.07603">pdf</a>, <a href="https://arxiv.org/format/2103.07603">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> </div> </div> <p class="title is-5 mathjax"> Multi-Resolution Electron Spectrometer Array for Future Free-Electron Laser Experiments </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Walter%2C+P">Peter Walter</a>, <a href="/search/physics?searchtype=author&query=Kamalov%2C+A">Andrei Kamalov</a>, <a href="/search/physics?searchtype=author&query=Gatton%2C+A">Averell Gatton</a>, <a href="/search/physics?searchtype=author&query=Driver%2C+T">Taran Driver</a>, <a href="/search/physics?searchtype=author&query=Bhogadi%2C+D">Dileep Bhogadi</a>, <a href="/search/physics?searchtype=author&query=Castagna%2C+J">Jean-Charles Castagna</a>, <a href="/search/physics?searchtype=author&query=Cheng%2C+X">Xianchao Cheng</a>, <a href="/search/physics?searchtype=author&query=Shi%2C+H">Hongliang Shi</a>, <a href="/search/physics?searchtype=author&query=Cryan%2C+J">James Cryan</a>, <a href="/search/physics?searchtype=author&query=Helml%2C+W">Wolfram Helml</a>, <a href="/search/physics?searchtype=author&query=Ilchen%2C+M">Markus Ilchen</a>, <a href="/search/physics?searchtype=author&query=Coffee%2C+R+N">Ryan N. Coffee</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="2103.07603v1-abstract-short" style="display: inline;"> We report the design of an angular array of electron Time-of-Flight (eToF) spectrometers intended for non-invasive spectral, temporal, and polarization characterization of single shots of high-repetition rate, quasi-continuous, short-wavelength Free-Electron Lasers (FELs) such as the LCLS-II at SLAC. This array also enables angle-resolved, high-resolution eToF spectroscopy to address a variety of… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2103.07603v1-abstract-full').style.display = 'inline'; document.getElementById('2103.07603v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2103.07603v1-abstract-full" style="display: none;"> We report the design of an angular array of electron Time-of-Flight (eToF) spectrometers intended for non-invasive spectral, temporal, and polarization characterization of single shots of high-repetition rate, quasi-continuous, short-wavelength Free-Electron Lasers (FELs) such as the LCLS-II at SLAC. This array also enables angle-resolved, high-resolution eToF spectroscopy to address a variety of scientific questions of ultrafast and nonlinear light--matter interaction at FELs. The presented device is specifically designed for the Time-resolved atomic, Molecular and Optical science end station (TMO) at LCLS-II. In its final version, it can comprise of up to 20 eToF spectrometers aligned to collect electrons from the interaction point defined by the intersection of the incoming FEL radiation and a gaseous target. There are 16 such spectrometers forming a circular equiangular array in the plane normal to x-ray propagation and 4 spectrometers at 54.7$^\circ$ angle relative to the principle linear x-ray polarization axis. The spectrometers are capable of independent and minimally chromatic electrostatic lensing and retardation in order to enable simultaneous angle-resolved photo-electron and Auger electron spectroscopy with high energy resolution. They are designed to ensure energy resolution of 0.25 eV across an energy window of up to 75 eV which can be individually centered via the adjustable retardation to cover ranges of electron kinetic energies relevant to soft x-ray methods, 0--2 keV. The full spectrometer array will enable non-invasive and online spectral-polarimetry measurements, polarization-sensitive attoclock spectroscopy for characterizing the full time--energy structure of even SASE or seeded LCLS-II pulses, and also supports emerging trends in molecular frame spectroscopy measurements. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2103.07603v1-abstract-full').style.display = 'none'; document.getElementById('2103.07603v1-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, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2021. </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">under review</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2012.07100">arXiv:2012.07100</a> <span> [<a href="https://arxiv.org/pdf/2012.07100">pdf</a>, <a href="https://arxiv.org/format/2012.07100">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Chemical Physics">physics.chem-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/10.1038/s42004-021-00555-6">10.1038/s42004-021-00555-6 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Site-specific Interrogation of an Ionic Chiral Fragment During Photolysis Using an X-ray Free-Electron Laser </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Ilchen%2C+M">Markus Ilchen</a>, <a href="/search/physics?searchtype=author&query=Schmidt%2C+P">Philipp Schmidt</a>, <a href="/search/physics?searchtype=author&query=Novikovskiy%2C+N+M">Nikolay M. Novikovskiy</a>, <a href="/search/physics?searchtype=author&query=Hartmann%2C+G">Gregor Hartmann</a>, <a href="/search/physics?searchtype=author&query=Rupprecht%2C+P">Patrick Rupprecht</a>, <a href="/search/physics?searchtype=author&query=Coffee%2C+R+N">Ryan N. Coffee</a>, <a href="/search/physics?searchtype=author&query=Ehresmann%2C+A">Arno Ehresmann</a>, <a href="/search/physics?searchtype=author&query=Galler%2C+A">Andreas Galler</a>, <a href="/search/physics?searchtype=author&query=Hartmann%2C+N">Nick Hartmann</a>, <a href="/search/physics?searchtype=author&query=Helml%2C+W">Wolfram Helml</a>, <a href="/search/physics?searchtype=author&query=Huang%2C+Z">Zhirong Huang</a>, <a href="/search/physics?searchtype=author&query=Inhester%2C+L">Ludger Inhester</a>, <a href="/search/physics?searchtype=author&query=Lutman%2C+A+A">Alberto A. Lutman</a>, <a href="/search/physics?searchtype=author&query=MacArthur%2C+J+P">James P. MacArthur</a>, <a href="/search/physics?searchtype=author&query=Maxwell%2C+T">Timothy Maxwell</a>, <a href="/search/physics?searchtype=author&query=Meyer%2C+M">Michael Meyer</a>, <a href="/search/physics?searchtype=author&query=Music%2C+V">Valerija Music</a>, <a href="/search/physics?searchtype=author&query=Nuhn%2C+H">Heinz-Dieter Nuhn</a>, <a href="/search/physics?searchtype=author&query=Osipov%2C+T">Timur Osipov</a>, <a href="/search/physics?searchtype=author&query=Ray%2C+D">Dipanwita Ray</a>, <a href="/search/physics?searchtype=author&query=Wolf%2C+T+J+A">Thomas J. A. Wolf</a>, <a href="/search/physics?searchtype=author&query=Bari%2C+S">Sadia Bari</a>, <a href="/search/physics?searchtype=author&query=Walter%2C+P">Peter Walter</a>, <a href="/search/physics?searchtype=author&query=Li%2C+Z">Zheng Li</a>, <a href="/search/physics?searchtype=author&query=Moeller%2C+S">Stefan Moeller</a> , et al. (2 additional authors not shown) </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="2012.07100v1-abstract-short" style="display: inline;"> Short-wavelength free-electron lasers with their ultrashort pulses at high intensities have originated new approaches for tracking molecular dynamics from the vista of specific sites. X-ray pump X-ray probe schemes even allow to address individual atomic constituents with a 'trigger'-event that preludes the subsequent molecular dynamics while being able to selectively probe the evolving structure… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.07100v1-abstract-full').style.display = 'inline'; document.getElementById('2012.07100v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2012.07100v1-abstract-full" style="display: none;"> Short-wavelength free-electron lasers with their ultrashort pulses at high intensities have originated new approaches for tracking molecular dynamics from the vista of specific sites. X-ray pump X-ray probe schemes even allow to address individual atomic constituents with a 'trigger'-event that preludes the subsequent molecular dynamics while being able to selectively probe the evolving structure with a time-delayed second X-ray pulse. Here, we use a linearly polarized X-ray photon to trigger the photolysis of a prototypical chiral molecule, namely trifluoromethyloxirane (C$_3$H$_3$F$_3$O), at the fluorine K-edge at around 700 eV. The evolving fluorine-containing fragments are then probed by a second, circularly polarized X-ray pulse of higher photon energy in order to investigate the chemically shifted inner-shell electrons of the ionic motherfragment for their stereochemical sensitivity. We experimentally demonstrate and theoretically support how two-color X-ray pump X-ray probe experiments with polarization control enable XFELs as tools for chiral recognition. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.07100v1-abstract-full').style.display = 'none'; document.getElementById('2012.07100v1-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 December, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2020. </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, 5 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/2009.12484">arXiv:2009.12484</a> <span> [<a href="https://arxiv.org/pdf/2009.12484">pdf</a>, <a href="https://arxiv.org/format/2009.12484">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="Instrumentation and Detectors">physics.ins-det</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/10.1038/s41598-021-82597-3">10.1038/s41598-021-82597-3 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A self-referenced in-situ arrival time monitor for X-ray free-electron lasers </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Diez%2C+M">Michael Diez</a>, <a href="/search/physics?searchtype=author&query=Galler%2C+A">Andreas Galler</a>, <a href="/search/physics?searchtype=author&query=Schulz%2C+S">Sebastian Schulz</a>, <a href="/search/physics?searchtype=author&query=Boemer%2C+C">Christina Boemer</a>, <a href="/search/physics?searchtype=author&query=Coffee%2C+R+N">Ryan N. Coffee</a>, <a href="/search/physics?searchtype=author&query=Hartmann%2C+N">Nick Hartmann</a>, <a href="/search/physics?searchtype=author&query=Heider%2C+R">Rupert Heider</a>, <a href="/search/physics?searchtype=author&query=Wagner%2C+M+S">Martin S. Wagner</a>, <a href="/search/physics?searchtype=author&query=Helml%2C+W">Wolfram Helml</a>, <a href="/search/physics?searchtype=author&query=Katayama%2C+T">Tetsuo Katayama</a>, <a href="/search/physics?searchtype=author&query=Sato%2C+T">Tokushi Sato</a>, <a href="/search/physics?searchtype=author&query=Sato%2C+T">Takahiro Sato</a>, <a href="/search/physics?searchtype=author&query=Yabashi%2C+M">Makina Yabashi</a>, <a href="/search/physics?searchtype=author&query=Bressler%2C+C">Christian Bressler</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="2009.12484v2-abstract-short" style="display: inline;"> We present a novel, highly versatile, and self-referenced arrival time monitor for measuring the femtosecond time delay between a hard X-ray pulse from a free-electron laser and an optical laser pulse, measured directly on the same sample used for pump-probe experiments. Two chirped and picosecond long optical supercontinuum pulses traverse the sample with a mutually fixed time delay of 970 fs, wh… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2009.12484v2-abstract-full').style.display = 'inline'; document.getElementById('2009.12484v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2009.12484v2-abstract-full" style="display: none;"> We present a novel, highly versatile, and self-referenced arrival time monitor for measuring the femtosecond time delay between a hard X-ray pulse from a free-electron laser and an optical laser pulse, measured directly on the same sample used for pump-probe experiments. Two chirped and picosecond long optical supercontinuum pulses traverse the sample with a mutually fixed time delay of 970 fs, while a femtosecond X-ray pulse arrives at an instant in between both pulses. Behind the sample the supercontinuum pulses are temporally overlapped to yield near-perfect destructive interference in the absence of the X-ray pulse. Stimulation of the sample with an X-ray pulse delivers non-zero contributions at certain optical wavelengths, which serve as a measure of the relative arrival time of the X-ray pulse with an accuracy of better than 25 fs. We find an excellent agreement of our monitor with the existing timing diagnostics at the SACLA XFEL with a Pearson correlation value of 0.98. We demonstrate a high sensitivity to measure X-ray pulses with pulse energies as low as 30 $渭$J. Using a free-flowing liquid jet as interaction sample ensures the full replacement of the sample volume for each X-ray/optical event, thus enabling its utility even at MHz repetition rate XFEL sources. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2009.12484v2-abstract-full').style.display = 'none'; document.getElementById('2009.12484v2-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 January, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 25 September, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Sci Rep 11, 3562 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2009.10914">arXiv:2009.10914</a> <span> [<a href="https://arxiv.org/pdf/2009.10914">pdf</a>, <a href="https://arxiv.org/format/2009.10914">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Accelerator Physics">physics.acc-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/PhysRevAccelBeams.23.120701">10.1103/PhysRevAccelBeams.23.120701 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Coherent X-rays with Tunable Time-Dependent Polarization </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Sudar%2C+N">Nicholas Sudar</a>, <a href="/search/physics?searchtype=author&query=Coffee%2C+R">Ryan Coffee</a>, <a href="/search/physics?searchtype=author&query=Hemsing%2C+E">Erik Hemsing</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="2009.10914v1-abstract-short" style="display: inline;"> We describe a method for producing high power, coherent x-ray pulses from a free electron laser with femtosecond scale periodic temporal modulation of the polarization vector. This approach relies on the generation of a temporal intensity modulation after self seeding either by modulating the seed intensity or the beam current. After generating a coherent temporally modulated $s$-polarization puls… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2009.10914v1-abstract-full').style.display = 'inline'; document.getElementById('2009.10914v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2009.10914v1-abstract-full" style="display: none;"> We describe a method for producing high power, coherent x-ray pulses from a free electron laser with femtosecond scale periodic temporal modulation of the polarization vector. This approach relies on the generation of a temporal intensity modulation after self seeding either by modulating the seed intensity or the beam current. After generating a coherent temporally modulated $s$-polarization pulse, the electron beam is delayed by half a modulation period and sent into a short orthogonally oriented undulator, serving as a $p$-polarization afterburner. We provide simulations of three configurations for realizing this polarization switching, namely, enhanced self seeding with an intensity modulation generated by 2 color self seeding, enhanced self seeding of a current modulated bunch, and regular self seeding of a current modulated bunch. Start to end simulations for the Linac Coherent Light Source-II are provided for the latter. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2009.10914v1-abstract-full').style.display = 'none'; document.getElementById('2009.10914v1-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 September, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2020. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2003.10398">arXiv:2003.10398</a> <span> [<a href="https://arxiv.org/pdf/2003.10398">pdf</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> </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/10.1038/s41567-020-01111-0">10.1038/s41567-020-01111-0 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Clocking Auger Electrons </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Haynes%2C+D+C">D. C. Haynes</a>, <a href="/search/physics?searchtype=author&query=Wurzer%2C+M">M. Wurzer</a>, <a href="/search/physics?searchtype=author&query=Schletter%2C+A">A. Schletter</a>, <a href="/search/physics?searchtype=author&query=Al-Haddad%2C+A">A. Al-Haddad</a>, <a href="/search/physics?searchtype=author&query=Blaga%2C+C">C. Blaga</a>, <a href="/search/physics?searchtype=author&query=Bostedt%2C+C">C. Bostedt</a>, <a href="/search/physics?searchtype=author&query=Bozek%2C+J">J. Bozek</a>, <a href="/search/physics?searchtype=author&query=Bucher%2C+M">M. Bucher</a>, <a href="/search/physics?searchtype=author&query=Camper%2C+A">A. Camper</a>, <a href="/search/physics?searchtype=author&query=Carron%2C+S">S. Carron</a>, <a href="/search/physics?searchtype=author&query=Coffee%2C+R">R. Coffee</a>, <a href="/search/physics?searchtype=author&query=Costello%2C+J+T">J. T. Costello</a>, <a href="/search/physics?searchtype=author&query=DiMauro%2C+L+F">L. F. DiMauro</a>, <a href="/search/physics?searchtype=author&query=Ding%2C+Y">Y. Ding</a>, <a href="/search/physics?searchtype=author&query=Ferguson%2C+K">K. Ferguson</a>, <a href="/search/physics?searchtype=author&query=Grgura%C5%A1%2C+I">I. Grgura拧</a>, <a href="/search/physics?searchtype=author&query=Helml%2C+W">W. Helml</a>, <a href="/search/physics?searchtype=author&query=Hoffmann%2C+M+C">M. C. Hoffmann</a>, <a href="/search/physics?searchtype=author&query=Ilchen%2C+M">M. Ilchen</a>, <a href="/search/physics?searchtype=author&query=Jalas%2C+S">S. Jalas</a>, <a href="/search/physics?searchtype=author&query=Kabachnik%2C+N+M">N. M. Kabachnik</a>, <a href="/search/physics?searchtype=author&query=Kazansky%2C+A+K">A. K. Kazansky</a>, <a href="/search/physics?searchtype=author&query=Kienberger%2C+R">R. Kienberger</a>, <a href="/search/physics?searchtype=author&query=Maier%2C+A+R">A. R. Maier</a>, <a href="/search/physics?searchtype=author&query=Maxwell%2C+T">T. Maxwell</a> , et al. (12 additional authors not shown) </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="2003.10398v1-abstract-short" style="display: inline;"> Intense X-ray free-electron lasers (XFELs) can rapidly excite matter, leaving it in inherently unstable states that decay on femtosecond timescales. As the relaxation occurs primarily via Auger emission, excited state observations are constrained by Auger decay. In situ measurement of this process is therefore crucial, yet it has thus far remained elusive at XFELs due to inherent timing and phase… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2003.10398v1-abstract-full').style.display = 'inline'; document.getElementById('2003.10398v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2003.10398v1-abstract-full" style="display: none;"> Intense X-ray free-electron lasers (XFELs) can rapidly excite matter, leaving it in inherently unstable states that decay on femtosecond timescales. As the relaxation occurs primarily via Auger emission, excited state observations are constrained by Auger decay. In situ measurement of this process is therefore crucial, yet it has thus far remained elusive at XFELs due to inherent timing and phase jitter, which can be orders of magnitude larger than the timescale of Auger decay. Here, we develop a new approach termed self-referenced attosecond streaking, based upon simultaneous measurements of streaked photo- and Auger electrons. Our technique enables sub-femtosecond resolution in spite of jitter. We exploit this method to make the first XFEL time-domain measurement of the Auger decay lifetime in atomic neon, and, by using a fully quantum-mechanical description, retrieve a lifetime of $2.2^{ + 0.2}_{ - 0.3}$ fs for the KLL decay channel. Importantly, our technique can be generalised to permit the extension of attosecond time-resolved experiments to all current and future FEL facilities. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2003.10398v1-abstract-full').style.display = 'none'; document.getElementById('2003.10398v1-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> 23 March, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2020. </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">Main text: 20 pages, 3 figures. Supplementary information: 17 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/1909.07441">arXiv:1909.07441</a> <span> [<a href="https://arxiv.org/pdf/1909.07441">pdf</a>, <a href="https://arxiv.org/format/1909.07441">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Chemical Physics">physics.chem-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-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/10.1039/C9CP03951A">10.1039/C9CP03951A <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Attosecond Transient Absorption Spooktroscopy: a ghost imaging approach to ultrafast absorption spectroscopy </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Driver%2C+T">Taran Driver</a>, <a href="/search/physics?searchtype=author&query=Li%2C+S">Siqi Li</a>, <a href="/search/physics?searchtype=author&query=Champenois%2C+E+G">Elio G. Champenois</a>, <a href="/search/physics?searchtype=author&query=Duris%2C+J">Joseph Duris</a>, <a href="/search/physics?searchtype=author&query=Ratner%2C+D">Daniel Ratner</a>, <a href="/search/physics?searchtype=author&query=Lane%2C+T">TJ Lane</a>, <a href="/search/physics?searchtype=author&query=Rosenberger%2C+P">Philipp Rosenberger</a>, <a href="/search/physics?searchtype=author&query=Al-Haddad%2C+A">Andre Al-Haddad</a>, <a href="/search/physics?searchtype=author&query=Averbukh%2C+V">Vitali Averbukh</a>, <a href="/search/physics?searchtype=author&query=Barnard%2C+T">Toby Barnard</a>, <a href="/search/physics?searchtype=author&query=Berrah%2C+N">Nora Berrah</a>, <a href="/search/physics?searchtype=author&query=Bostedt%2C+C">Christoph Bostedt</a>, <a href="/search/physics?searchtype=author&query=Bucksbaum%2C+P+H">Philip H. Bucksbaum</a>, <a href="/search/physics?searchtype=author&query=Coffee%2C+R">Ryan Coffee</a>, <a href="/search/physics?searchtype=author&query=DiMauro%2C+L+F">Louis F. DiMauro</a>, <a href="/search/physics?searchtype=author&query=Fang%2C+L">Li Fang</a>, <a href="/search/physics?searchtype=author&query=Garratt%2C+D">Douglas Garratt</a>, <a href="/search/physics?searchtype=author&query=Gatton%2C+A">Averell Gatton</a>, <a href="/search/physics?searchtype=author&query=Guo%2C+Z">Zhaoheng Guo</a>, <a href="/search/physics?searchtype=author&query=Hartmann%2C+G">Gregor Hartmann</a>, <a href="/search/physics?searchtype=author&query=Haxton%2C+D">Daniel Haxton</a>, <a href="/search/physics?searchtype=author&query=Helml%2C+W">Wolfram Helml</a>, <a href="/search/physics?searchtype=author&query=Huang%2C+Z">Zhirong Huang</a>, <a href="/search/physics?searchtype=author&query=LaForge%2C+A">Aaron LaForge</a>, <a href="/search/physics?searchtype=author&query=Kamalov%2C+A">Andrei Kamalov</a> , et al. (16 additional authors not shown) </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="1909.07441v1-abstract-short" style="display: inline;"> The recent demonstration of isolated attosecond pulses from an X-ray free-electron laser (XFEL) opens the possibility for probing ultrafast electron dynamics at X-ray wavelengths. An established experimental method for probing ultrafast dynamics is X-ray transient absorption spectroscopy, where the X-ray absorption spectrum is measured by scanning the central photon energy and recording the result… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1909.07441v1-abstract-full').style.display = 'inline'; document.getElementById('1909.07441v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1909.07441v1-abstract-full" style="display: none;"> The recent demonstration of isolated attosecond pulses from an X-ray free-electron laser (XFEL) opens the possibility for probing ultrafast electron dynamics at X-ray wavelengths. An established experimental method for probing ultrafast dynamics is X-ray transient absorption spectroscopy, where the X-ray absorption spectrum is measured by scanning the central photon energy and recording the resultant photoproducts. The spectral bandwidth inherent to attosecond pulses is wide compared to the resonant features typically probed, which generally precludes the application of this technique in the attosecond regime. In this paper we propose and demonstrate a new technique to conduct transient absorption spectroscopy with broad bandwidth attosecond pulses with the aid of ghost imaging, recovering sub-bandwidth resolution in photoproduct-based absorption measurements. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1909.07441v1-abstract-full').style.display = 'none'; document.getElementById('1909.07441v1-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 September, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 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">13 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/1906.10649">arXiv:1906.10649</a> <span> [<a href="https://arxiv.org/pdf/1906.10649">pdf</a>, <a href="https://arxiv.org/format/1906.10649">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="Accelerator Physics">physics.acc-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/10.1038/s41566-019-0549-5">10.1038/s41566-019-0549-5 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Tunable Isolated Attosecond X-ray Pulses with Gigawatt Peak Power from a Free-Electron Laser </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Duris%2C+J">Joseph Duris</a>, <a href="/search/physics?searchtype=author&query=Li%2C+S">Siqi Li</a>, <a href="/search/physics?searchtype=author&query=Driver%2C+T">Taran Driver</a>, <a href="/search/physics?searchtype=author&query=Champenois%2C+E+G">Elio G. Champenois</a>, <a href="/search/physics?searchtype=author&query=MacArthur%2C+J+P">James P. MacArthur</a>, <a href="/search/physics?searchtype=author&query=Lutman%2C+A+A">Alberto A. Lutman</a>, <a href="/search/physics?searchtype=author&query=Zhang%2C+Z">Zhen Zhang</a>, <a href="/search/physics?searchtype=author&query=Rosenberger%2C+P">Philipp Rosenberger</a>, <a href="/search/physics?searchtype=author&query=Aldrich%2C+J+W">Jeff W. Aldrich</a>, <a href="/search/physics?searchtype=author&query=Coffee%2C+R">Ryan Coffee</a>, <a href="/search/physics?searchtype=author&query=Coslovich%2C+G">Giacomo Coslovich</a>, <a href="/search/physics?searchtype=author&query=Decker%2C+F">Franz-Josef Decker</a>, <a href="/search/physics?searchtype=author&query=Glownia%2C+J+M">James M. Glownia</a>, <a href="/search/physics?searchtype=author&query=Hartmann%2C+G">Gregor Hartmann</a>, <a href="/search/physics?searchtype=author&query=Helml%2C+W">Wolfram Helml</a>, <a href="/search/physics?searchtype=author&query=Kamalov%2C+A">Andrei Kamalov</a>, <a href="/search/physics?searchtype=author&query=Knurr%2C+J">Jonas Knurr</a>, <a href="/search/physics?searchtype=author&query=Krzywinski%2C+J">Jacek Krzywinski</a>, <a href="/search/physics?searchtype=author&query=Lin%2C+M">Ming-Fu Lin</a>, <a href="/search/physics?searchtype=author&query=Nantel%2C+M">Megan Nantel</a>, <a href="/search/physics?searchtype=author&query=Natan%2C+A">Adi Natan</a>, <a href="/search/physics?searchtype=author&query=O%27Neal%2C+J">Jordan O'Neal</a>, <a href="/search/physics?searchtype=author&query=Shivaram%2C+N">Niranjan Shivaram</a>, <a href="/search/physics?searchtype=author&query=Walter%2C+P">Peter Walter</a>, <a href="/search/physics?searchtype=author&query=Wang%2C+A">Anna Wang</a> , et al. (9 additional authors not shown) </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="1906.10649v1-abstract-short" style="display: inline;"> The quantum mechanical motion of electrons in molecules and solids occurs on the sub-femtosecond timescale. Consequently, the study of ultrafast electronic phenomena requires the generation of laser pulses shorter than 1 fs and of sufficient intensity to interact with their target with high probability. Probing these dynamics with atomic-site specificity requires the extension of sub-femtosecond p… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1906.10649v1-abstract-full').style.display = 'inline'; document.getElementById('1906.10649v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1906.10649v1-abstract-full" style="display: none;"> The quantum mechanical motion of electrons in molecules and solids occurs on the sub-femtosecond timescale. Consequently, the study of ultrafast electronic phenomena requires the generation of laser pulses shorter than 1 fs and of sufficient intensity to interact with their target with high probability. Probing these dynamics with atomic-site specificity requires the extension of sub-femtosecond pulses to the soft X-ray spectral region. Here we report the generation of isolated GW-scale soft X-ray attosecond pulses with an X-ray free-electron laser. Our source has a pulse energy that is six orders of magnitude larger than any other source of isolated attosecond pulses in the soft X-ray spectral region, with a peak power in the tens of gigawatts. This unique combination of high intensity, high photon energy and short pulse duration enables the investigation of electron dynamics with X-ray non-linear spectroscopy and single-particle imaging. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1906.10649v1-abstract-full').style.display = 'none'; document.getElementById('1906.10649v1-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, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Duris, J., Li, S., Driver, T. et al. Nat. Photonics 14, 30-36 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1810.02900">arXiv:1810.02900</a> <span> [<a href="https://arxiv.org/pdf/1810.02900">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Chemical Physics">physics.chem-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/10.1038/s41557-019-0252-7">10.1038/s41557-019-0252-7 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Imaging the Photochemical Ring-Opening of 1,3-Cyclohexadiene by Ultrafast Electron Diffraction </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Wolf%2C+T+J+A">T. J. A. Wolf</a>, <a href="/search/physics?searchtype=author&query=Sanchez%2C+D+M">D. M. Sanchez</a>, <a href="/search/physics?searchtype=author&query=Yang%2C+J">J. Yang</a>, <a href="/search/physics?searchtype=author&query=Parrish%2C+R+M">R. M. Parrish</a>, <a href="/search/physics?searchtype=author&query=Nunes%2C+J+P+F">J. P. F. Nunes</a>, <a href="/search/physics?searchtype=author&query=Centurion%2C+M">M. Centurion</a>, <a href="/search/physics?searchtype=author&query=Coffee%2C+R">R. Coffee</a>, <a href="/search/physics?searchtype=author&query=Cryan%2C+J+P">J. P. Cryan</a>, <a href="/search/physics?searchtype=author&query=G%C3%BChr%2C+M">M. G眉hr</a>, <a href="/search/physics?searchtype=author&query=Hegazy%2C+K">K. Hegazy</a>, <a href="/search/physics?searchtype=author&query=Kirrander%2C+A">A. Kirrander</a>, <a href="/search/physics?searchtype=author&query=Li%2C+R+K">R. K. Li</a>, <a href="/search/physics?searchtype=author&query=Ruddock%2C+J">J. Ruddock</a>, <a href="/search/physics?searchtype=author&query=Shen%2C+X">X. Shen</a>, <a href="/search/physics?searchtype=author&query=Veccione%2C+T">T. Veccione</a>, <a href="/search/physics?searchtype=author&query=Weathersby%2C+S+P">S. P. Weathersby</a>, <a href="/search/physics?searchtype=author&query=Weber%2C+P+M">P. M. Weber</a>, <a href="/search/physics?searchtype=author&query=Wilkin%2C+K">K. Wilkin</a>, <a href="/search/physics?searchtype=author&query=Yong%2C+H">H. Yong</a>, <a href="/search/physics?searchtype=author&query=Zheng%2C+Q">Q. Zheng</a>, <a href="/search/physics?searchtype=author&query=Wang%2C+X+J">X. J. Wang</a>, <a href="/search/physics?searchtype=author&query=Minitti%2C+M+P">M. P. Minitti</a>, <a href="/search/physics?searchtype=author&query=Mart%C3%ADnez%2C+T+J">T. J. Mart铆nez</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="1810.02900v1-abstract-short" style="display: inline;"> The ultrafast photoinduced ring-opening of 1,3-cyclohexadiene constitutes a textbook example of electrocyclic reactions in organic chemistry and a model for photobiological reactions in vitamin D synthesis. Here, we present direct and unambiguous observation of the ring-opening reaction path on the femtosecond timescale and sub-脜ngstr枚m length scale by megaelectronvolt ultrafast electron diffracti… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1810.02900v1-abstract-full').style.display = 'inline'; document.getElementById('1810.02900v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1810.02900v1-abstract-full" style="display: none;"> The ultrafast photoinduced ring-opening of 1,3-cyclohexadiene constitutes a textbook example of electrocyclic reactions in organic chemistry and a model for photobiological reactions in vitamin D synthesis. Here, we present direct and unambiguous observation of the ring-opening reaction path on the femtosecond timescale and sub-脜ngstr枚m length scale by megaelectronvolt ultrafast electron diffraction. We follow the carbon-carbon bond dissociation and the structural opening of the 1,3-cyclohexadiene ring by direct measurement of time-dependent changes in the distribution of interatomic distances. We observe a substantial acceleration of the ring-opening motion after internal conversion to the ground state due to steepening of the electronic potential gradient towards the product minima. The ring-opening motion transforms into rotation of the terminal ethylene groups in the photoproduct 1,3,5-hexatriene on the sub-picosecond timescale. Our work demonstrates the potential of megaelectronvolt ultrafast electron diffraction to elucidate photochemical reaction paths in organic chemistry. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1810.02900v1-abstract-full').style.display = 'none'; document.getElementById('1810.02900v1-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> 5 October, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2018. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1705.01938">arXiv:1705.01938</a> <span> [<a href="https://arxiv.org/pdf/1705.01938">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Accelerator Physics">physics.acc-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</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/10.1088/1367-2630/aab548">10.1088/1367-2630/aab548 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Femtosecond profiling of shaped X-ray pulses </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Hoffmann%2C+M+C">M. C. Hoffmann</a>, <a href="/search/physics?searchtype=author&query=Grgura%C5%A1%2C+I">I. Grgura拧</a>, <a href="/search/physics?searchtype=author&query=Behrens%2C+C">C. Behrens</a>, <a href="/search/physics?searchtype=author&query=Bostedt%2C+C">C. Bostedt</a>, <a href="/search/physics?searchtype=author&query=Bozek%2C+J">J. Bozek</a>, <a href="/search/physics?searchtype=author&query=Bromberger%2C+H">H. Bromberger</a>, <a href="/search/physics?searchtype=author&query=Coffee%2C+R">R. Coffee</a>, <a href="/search/physics?searchtype=author&query=Costello%2C+J+T">J. T. Costello</a>, <a href="/search/physics?searchtype=author&query=DiMauro%2C+L+F">L. F. DiMauro</a>, <a href="/search/physics?searchtype=author&query=Ding%2C+Y">Y. Ding</a>, <a href="/search/physics?searchtype=author&query=Doumy%2C+G">G. Doumy</a>, <a href="/search/physics?searchtype=author&query=Helml%2C+W">W. Helml</a>, <a href="/search/physics?searchtype=author&query=Ilchen%2C+M">M. Ilchen</a>, <a href="/search/physics?searchtype=author&query=Kienberger%2C+R">R. Kienberger</a>, <a href="/search/physics?searchtype=author&query=Lee%2C+S">S. Lee</a>, <a href="/search/physics?searchtype=author&query=Maier%2C+A+R">A. R. Maier</a>, <a href="/search/physics?searchtype=author&query=Mazza%2C+T">T. Mazza</a>, <a href="/search/physics?searchtype=author&query=Meyer%2C+M">M. Meyer</a>, <a href="/search/physics?searchtype=author&query=Messerschmidt%2C+M">M. Messerschmidt</a>, <a href="/search/physics?searchtype=author&query=Schorb%2C+S">S. Schorb</a>, <a href="/search/physics?searchtype=author&query=Schweinberger%2C+W">W. Schweinberger</a>, <a href="/search/physics?searchtype=author&query=Zhang%2C+K">K. Zhang</a>, <a href="/search/physics?searchtype=author&query=Cavalieri%2C+A+L">A. L. Cavalieri</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="1705.01938v1-abstract-short" style="display: inline;"> Arbitrary manipulation of the temporal and spectral properties of X-ray pulses at free-electron lasers (FELs) would revolutionize many experimental applications. At the Linac Coherent Light Source at Stanford National Accelerator Laboratory, the momentum phase-space of the FEL driving electron bunch can be tuned to emit a pair of X-ray pulses with independently variable photon energy and femtoseco… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1705.01938v1-abstract-full').style.display = 'inline'; document.getElementById('1705.01938v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1705.01938v1-abstract-full" style="display: none;"> Arbitrary manipulation of the temporal and spectral properties of X-ray pulses at free-electron lasers (FELs) would revolutionize many experimental applications. At the Linac Coherent Light Source at Stanford National Accelerator Laboratory, the momentum phase-space of the FEL driving electron bunch can be tuned to emit a pair of X-ray pulses with independently variable photon energy and femtosecond delay. However, while accelerator parameters can easily be adjusted to tune the electron bunch phase-space, the final impact of these actuators on the X-ray pulse cannot be predicted with sufficient precision. Furthermore, shot-to-shot instabilities that distort the pulse shape unpredictably cannot be fully suppressed. Therefore, the ability to directly characterize the X-rays is essential to ensure precise and consistent control. In this work, we have generated X-ray pulse pairs and characterized them on a single-shot basis with femtosecond resolution through time-resolved photoelectron streaking spectroscopy. This achievement completes an important step toward future X-ray pulse shaping techniques. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1705.01938v1-abstract-full').style.display = 'none'; document.getElementById('1705.01938v1-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> 4 May, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2017. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1704.02265">arXiv:1704.02265</a> <span> [<a href="https://arxiv.org/pdf/1704.02265">pdf</a>, <a href="https://arxiv.org/format/1704.02265">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Chemical Physics">physics.chem-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.95.053423">10.1103/PhysRevA.95.053423 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Emitter-site selective photoelectron circular dichroism of trifluoromethyloxirane </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Ilchen%2C+M">M. Ilchen</a>, <a href="/search/physics?searchtype=author&query=Hartmann%2C+G">G. Hartmann</a>, <a href="/search/physics?searchtype=author&query=Rupprecht%2C+P">P. Rupprecht</a>, <a href="/search/physics?searchtype=author&query=Artemyev%2C+A+N">A. N. Artemyev</a>, <a href="/search/physics?searchtype=author&query=Coffee%2C+R+N">R. N. Coffee</a>, <a href="/search/physics?searchtype=author&query=Li%2C+Z">Z. Li</a>, <a href="/search/physics?searchtype=author&query=Ohldag%2C+H">H. Ohldag</a>, <a href="/search/physics?searchtype=author&query=Ogasawara%2C+H">H. Ogasawara</a>, <a href="/search/physics?searchtype=author&query=Osipov%2C+T">T. Osipov</a>, <a href="/search/physics?searchtype=author&query=Ray%2C+D">D. Ray</a>, <a href="/search/physics?searchtype=author&query=Schmidt%2C+P">Ph. Schmidt</a>, <a href="/search/physics?searchtype=author&query=Wolf%2C+T+J+A">T. J. A. Wolf</a>, <a href="/search/physics?searchtype=author&query=Ehresmann%2C+A">A. Ehresmann</a>, <a href="/search/physics?searchtype=author&query=Moeller%2C+S">S. Moeller</a>, <a href="/search/physics?searchtype=author&query=Knie%2C+A">A. Knie</a>, <a href="/search/physics?searchtype=author&query=Demekhin%2C+P+V">Ph. V. Demekhin</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="1704.02265v1-abstract-short" style="display: inline;"> The angle-resolved inner-shell photoionization of R-trifluoromethyloxirane, C3H3F3O, is studied experimentally and theoretically. Thereby, we investigate the photoelectron circular dichroism (PECD) for nearly-symmetric O 1s and F 1s electronic orbitals, which are localized on different molecular sites. The respective dichroic $尾_{1}$ and angular distribution $尾_{2}$ parameters are measured at the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1704.02265v1-abstract-full').style.display = 'inline'; document.getElementById('1704.02265v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1704.02265v1-abstract-full" style="display: none;"> The angle-resolved inner-shell photoionization of R-trifluoromethyloxirane, C3H3F3O, is studied experimentally and theoretically. Thereby, we investigate the photoelectron circular dichroism (PECD) for nearly-symmetric O 1s and F 1s electronic orbitals, which are localized on different molecular sites. The respective dichroic $尾_{1}$ and angular distribution $尾_{2}$ parameters are measured at the photoelectron kinetic energies from 1 to 16 eV by using variably polarized synchrotron radiation and velocity map imaging spectroscopy. The present experimental results are in good agreement with the outcome of ab initio electronic structure calculations. We report a sizable chiral asymmetry $尾_{1}$ of up to about 9% for the K-shell photoionization of oxygen atom. For the individual fluorine atoms, the present calculations predict asymmetries of similar size. However, being averaged over all fluorine atoms, it drops down to about 2%, as also observed in the present experiment. Our study demonstrates a strong emitter- and site-sensitivity of PECD in the one-photon inner-shell ionization of this chiral molecule. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1704.02265v1-abstract-full').style.display = 'none'; document.getElementById('1704.02265v1-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 April, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2017. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. A 95, 053423 (2017) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1610.03378">arXiv:1610.03378</a> <span> [<a href="https://arxiv.org/pdf/1610.03378">pdf</a>, <a href="https://arxiv.org/format/1610.03378">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Data Analysis, Statistics and Probability">physics.data-an</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Accelerator Physics">physics.acc-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Machine Learning">stat.ML</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/10.1038/ncomms15461">10.1038/ncomms15461 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Machine learning applied to single-shot x-ray diagnostics in an XFEL </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Sanchez-Gonzalez%2C+A">A. Sanchez-Gonzalez</a>, <a href="/search/physics?searchtype=author&query=Micaelli%2C+P">P. Micaelli</a>, <a href="/search/physics?searchtype=author&query=Olivier%2C+C">C. Olivier</a>, <a href="/search/physics?searchtype=author&query=Barillot%2C+T+R">T. R. Barillot</a>, <a href="/search/physics?searchtype=author&query=Ilchen%2C+M">M. Ilchen</a>, <a href="/search/physics?searchtype=author&query=Lutman%2C+A+A">A. A. Lutman</a>, <a href="/search/physics?searchtype=author&query=Marinelli%2C+A">A. Marinelli</a>, <a href="/search/physics?searchtype=author&query=Maxwell%2C+T">T. Maxwell</a>, <a href="/search/physics?searchtype=author&query=Achner%2C+A">A. Achner</a>, <a href="/search/physics?searchtype=author&query=Ag%C3%A5ker%2C+M">M. Ag氓ker</a>, <a href="/search/physics?searchtype=author&query=Berrah%2C+N">N. Berrah</a>, <a href="/search/physics?searchtype=author&query=Bostedt%2C+C">C. Bostedt</a>, <a href="/search/physics?searchtype=author&query=Buck%2C+J">J. Buck</a>, <a href="/search/physics?searchtype=author&query=Bucksbaum%2C+P+H">P. H. Bucksbaum</a>, <a href="/search/physics?searchtype=author&query=Montero%2C+S+C">S. Carron Montero</a>, <a href="/search/physics?searchtype=author&query=Cooper%2C+B">B. Cooper</a>, <a href="/search/physics?searchtype=author&query=Cryan%2C+J+P">J. P. Cryan</a>, <a href="/search/physics?searchtype=author&query=Dong%2C+M">M. Dong</a>, <a href="/search/physics?searchtype=author&query=Feifel%2C+R">R. Feifel</a>, <a href="/search/physics?searchtype=author&query=Frasinski%2C+L+J">L. J. Frasinski</a>, <a href="/search/physics?searchtype=author&query=Fukuzawa%2C+H">H. Fukuzawa</a>, <a href="/search/physics?searchtype=author&query=Galler%2C+A">A. Galler</a>, <a href="/search/physics?searchtype=author&query=Hartmann%2C+G">G. Hartmann</a>, <a href="/search/physics?searchtype=author&query=Hartmann%2C+N">N. Hartmann</a>, <a href="/search/physics?searchtype=author&query=Helml%2C+W">W. Helml</a> , et al. (17 additional authors not shown) </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="1610.03378v1-abstract-short" style="display: inline;"> X-ray free-electron lasers (XFELs) are the only sources currently able to produce bright few-fs pulses with tunable photon energies from 100 eV to more than 10 keV. Due to the stochastic SASE operating principles and other technical issues the output pulses are subject to large fluctuations, making it necessary to characterize the x-ray pulses on every shot for data sorting purposes. We present a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1610.03378v1-abstract-full').style.display = 'inline'; document.getElementById('1610.03378v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1610.03378v1-abstract-full" style="display: none;"> X-ray free-electron lasers (XFELs) are the only sources currently able to produce bright few-fs pulses with tunable photon energies from 100 eV to more than 10 keV. Due to the stochastic SASE operating principles and other technical issues the output pulses are subject to large fluctuations, making it necessary to characterize the x-ray pulses on every shot for data sorting purposes. We present a technique that applies machine learning tools to predict x-ray pulse properties using simple electron beam and x-ray parameters as input. Using this technique at the Linac Coherent Light Source (LCLS), we report mean errors below 0.3 eV for the prediction of the photon energy at 530 eV and below 1.6 fs for the prediction of the delay between two x-ray pulses. We also demonstrate spectral shape prediction with a mean agreement of 97%. This approach could potentially be used at the next generation of high-repetition-rate XFELs to provide accurate knowledge of complex x-ray pulses at the full repetition rate. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1610.03378v1-abstract-full').style.display = 'none'; document.getElementById('1610.03378v1-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 October, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2016. </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, 8 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Nature Communications 8, 15461 (2017) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1608.07725">arXiv:1608.07725</a> <span> [<a href="https://arxiv.org/pdf/1608.07725">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Chemical Physics">physics.chem-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.117.153002">10.1103/PhysRevLett.117.153002 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Diffractive Imaging of Coherent Nuclear Motion in Isolated Molecules </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Yang%2C+J">Jie Yang</a>, <a href="/search/physics?searchtype=author&query=Guehr%2C+M">Markus Guehr</a>, <a href="/search/physics?searchtype=author&query=Shen%2C+X">Xiaozhe Shen</a>, <a href="/search/physics?searchtype=author&query=Li%2C+R">Renkai Li</a>, <a href="/search/physics?searchtype=author&query=Vecchione%2C+T">Theodore Vecchione</a>, <a href="/search/physics?searchtype=author&query=Coffee%2C+R">Ryan Coffee</a>, <a href="/search/physics?searchtype=author&query=Corbett%2C+J">Jeff Corbett</a>, <a href="/search/physics?searchtype=author&query=Fry%2C+A">Alan Fry</a>, <a href="/search/physics?searchtype=author&query=Hartmann%2C+N">Nick Hartmann</a>, <a href="/search/physics?searchtype=author&query=Hast%2C+C">Carsten Hast</a>, <a href="/search/physics?searchtype=author&query=Hegazy%2C+K">Kareem Hegazy</a>, <a href="/search/physics?searchtype=author&query=Jobe%2C+K">Keith Jobe</a>, <a href="/search/physics?searchtype=author&query=Makasyuk%2C+I">Igor Makasyuk</a>, <a href="/search/physics?searchtype=author&query=Robinson%2C+J">Joseph Robinson</a>, <a href="/search/physics?searchtype=author&query=Robinson%2C+M+S">Matthew S. Robinson</a>, <a href="/search/physics?searchtype=author&query=Vetter%2C+S">Sharon Vetter</a>, <a href="/search/physics?searchtype=author&query=Weathersby%2C+S">Stephen Weathersby</a>, <a href="/search/physics?searchtype=author&query=Yoneda%2C+C">Charles Yoneda</a>, <a href="/search/physics?searchtype=author&query=Wang%2C+X">Xijie Wang</a>, <a href="/search/physics?searchtype=author&query=Centurion%2C+M">Martin Centurion</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="1608.07725v1-abstract-short" style="display: inline;"> Observing the motion of the nuclear wavepackets during a molecular reaction, in both space and time, is crucial for understanding and controlling the outcome of photoinduced chemical reactions. We have imaged the motion of a vibrational wavepacket in isolated iodine molecules using ultrafast electron diffraction with relativistic electrons. The time-varying interatomic distance was measured with a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1608.07725v1-abstract-full').style.display = 'inline'; document.getElementById('1608.07725v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1608.07725v1-abstract-full" style="display: none;"> Observing the motion of the nuclear wavepackets during a molecular reaction, in both space and time, is crucial for understanding and controlling the outcome of photoinduced chemical reactions. We have imaged the motion of a vibrational wavepacket in isolated iodine molecules using ultrafast electron diffraction with relativistic electrons. The time-varying interatomic distance was measured with a precision 0.07 脜 and temporal resolution of 230 fs full-width at half-maximum (FWHM). The method is not only sensitive to the position but also the shape of the nuclear wavepacket. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1608.07725v1-abstract-full').style.display = 'none'; document.getElementById('1608.07725v1-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 August, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2016. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1510.06426">arXiv:1510.06426</a> <span> [<a href="https://arxiv.org/pdf/1510.06426">pdf</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> </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/10.1038/ncomms11232">10.1038/ncomms11232 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Diffractive imaging of a molecular rotational wavepacket with femtosecond Megaelectronvolt electron pulses </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Yang%2C+J">Jie Yang</a>, <a href="/search/physics?searchtype=author&query=Guehr%2C+M">Markus Guehr</a>, <a href="/search/physics?searchtype=author&query=Vecchione%2C+T">Theodore Vecchione</a>, <a href="/search/physics?searchtype=author&query=Robinson%2C+M+S">Matthew S. Robinson</a>, <a href="/search/physics?searchtype=author&query=Li%2C+R">Renkai Li</a>, <a href="/search/physics?searchtype=author&query=Hartmann%2C+N">Nick Hartmann</a>, <a href="/search/physics?searchtype=author&query=Shen%2C+X">Xiaozhe Shen</a>, <a href="/search/physics?searchtype=author&query=Coffee%2C+R">Ryan Coffee</a>, <a href="/search/physics?searchtype=author&query=Corbett%2C+J">Jeff Corbett</a>, <a href="/search/physics?searchtype=author&query=Fry%2C+A">Alan Fry</a>, <a href="/search/physics?searchtype=author&query=Gaffney%2C+K">Kelly Gaffney</a>, <a href="/search/physics?searchtype=author&query=Gorkhover%2C+T">Tais Gorkhover</a>, <a href="/search/physics?searchtype=author&query=Hast%2C+C">Carsten Hast</a>, <a href="/search/physics?searchtype=author&query=Jobe%2C+K">Keith Jobe</a>, <a href="/search/physics?searchtype=author&query=Makasyuk%2C+I">Igor Makasyuk</a>, <a href="/search/physics?searchtype=author&query=Reid%2C+A">Alexander Reid</a>, <a href="/search/physics?searchtype=author&query=Robinson%2C+J">Joseph Robinson</a>, <a href="/search/physics?searchtype=author&query=Vetter%2C+S">Sharon Vetter</a>, <a href="/search/physics?searchtype=author&query=Wang%2C+F">Fenglin Wang</a>, <a href="/search/physics?searchtype=author&query=Weathersby%2C+S">Stephen Weathersby</a>, <a href="/search/physics?searchtype=author&query=Yoneda%2C+C">Charles Yoneda</a>, <a href="/search/physics?searchtype=author&query=Centurion%2C+M">Martin Centurion</a>, <a href="/search/physics?searchtype=author&query=Wang%2C+X">Xijie Wang</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="1510.06426v1-abstract-short" style="display: inline;"> Imaging changes in molecular geometries on their natural femtosecond timescale with sub-Angstrom spatial precision is one of the critical challenges in the chemical sciences, since the nuclear geometry changes determine the molecular reactivity. For photoexcited molecules, the nuclear dynamics determine the photoenergy conversion path and efficiency. We performed a gas-phase electron diffraction e… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1510.06426v1-abstract-full').style.display = 'inline'; document.getElementById('1510.06426v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1510.06426v1-abstract-full" style="display: none;"> Imaging changes in molecular geometries on their natural femtosecond timescale with sub-Angstrom spatial precision is one of the critical challenges in the chemical sciences, since the nuclear geometry changes determine the molecular reactivity. For photoexcited molecules, the nuclear dynamics determine the photoenergy conversion path and efficiency. We performed a gas-phase electron diffraction experiment using Megaelectronvolt (MeV) electrons, where we captured the rotational wavepacket dynamics of nonadiabatically laser-aligned nitrogen molecules. We achieved an unprecedented combination of 100 fs root-mean-squared (RMS) temporal resolution and sub-Angstrom (0.76 脜) spatial resolution that makes it possible to resolve the position of the nuclei within the molecule. In addition, the diffraction patterns reveal the angular distribution of the molecules, which changes from prolate (aligned) to oblate (anti-aligned) in 300 fs. Our results demonstrate a significant and promising step towards making atomically resolved movies of molecular reactions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1510.06426v1-abstract-full').style.display = 'none'; document.getElementById('1510.06426v1-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, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2015. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1407.7782">arXiv:1407.7782</a> <span> [<a href="https://arxiv.org/pdf/1407.7782">pdf</a>, <a href="https://arxiv.org/format/1407.7782">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> </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/10.1039/C4FD00037D">10.1039/C4FD00037D <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Imaging Molecular Structure through Femtosecond Photoelectron Diffraction on Aligned and Oriented Gas-Phase Molecules </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Boll%2C+R">R. Boll</a>, <a href="/search/physics?searchtype=author&query=Rouzee%2C+A">A. Rouzee</a>, <a href="/search/physics?searchtype=author&query=Adolph%2C+M">M. Adolph</a>, <a href="/search/physics?searchtype=author&query=Anielski%2C+D">D. Anielski</a>, <a href="/search/physics?searchtype=author&query=Aquila%2C+A">A. Aquila</a>, <a href="/search/physics?searchtype=author&query=Bari%2C+S">S. Bari</a>, <a href="/search/physics?searchtype=author&query=Bomme%2C+C">C. Bomme</a>, <a href="/search/physics?searchtype=author&query=Bostedt%2C+C">C. Bostedt</a>, <a href="/search/physics?searchtype=author&query=Bozek%2C+J+D">J. D. Bozek</a>, <a href="/search/physics?searchtype=author&query=Chapman%2C+H+N">H. N. Chapman</a>, <a href="/search/physics?searchtype=author&query=Christensen%2C+L">L. Christensen</a>, <a href="/search/physics?searchtype=author&query=Coffee%2C+R">R. Coffee</a>, <a href="/search/physics?searchtype=author&query=Coppola%2C+N">N. Coppola</a>, <a href="/search/physics?searchtype=author&query=De%2C+S">S. De</a>, <a href="/search/physics?searchtype=author&query=Decleva%2C+P">P. Decleva</a>, <a href="/search/physics?searchtype=author&query=Epp%2C+S+W">S. W. Epp</a>, <a href="/search/physics?searchtype=author&query=Erk%2C+B">B. Erk</a>, <a href="/search/physics?searchtype=author&query=Filsinger%2C+F">F. Filsinger</a>, <a href="/search/physics?searchtype=author&query=Foucar%2C+L">L. Foucar</a>, <a href="/search/physics?searchtype=author&query=Gorkhover%2C+T">T. Gorkhover</a>, <a href="/search/physics?searchtype=author&query=Gumprecht%2C+L">L. Gumprecht</a>, <a href="/search/physics?searchtype=author&query=Hoemke%2C+A">A. Hoemke</a>, <a href="/search/physics?searchtype=author&query=Holmegaard%2C+L">L. Holmegaard</a>, <a href="/search/physics?searchtype=author&query=Johnsson%2C+P">P. Johnsson</a>, <a href="/search/physics?searchtype=author&query=Kienitz%2C+J+S">J. S. Kienitz</a> , et al. (27 additional authors not shown) </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="1407.7782v1-abstract-short" style="display: inline;"> This paper gives an account of our progress towards performing femtosecond time-resolved photoelectron diffraction on gas-phase molecules in a pump-probe setup combining optical lasers and an X-ray Free-Electron Laser. We present results of two experiments aimed at measuring photoelectron angular distributions of laser-aligned 1-ethynyl-4-fluorobenzene (C8H5F) and dissociating, laseraligned 1,4-di… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1407.7782v1-abstract-full').style.display = 'inline'; document.getElementById('1407.7782v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1407.7782v1-abstract-full" style="display: none;"> This paper gives an account of our progress towards performing femtosecond time-resolved photoelectron diffraction on gas-phase molecules in a pump-probe setup combining optical lasers and an X-ray Free-Electron Laser. We present results of two experiments aimed at measuring photoelectron angular distributions of laser-aligned 1-ethynyl-4-fluorobenzene (C8H5F) and dissociating, laseraligned 1,4-dibromobenzene (C6H4Br2) molecules and discuss them in the larger context of photoelectron diffraction on gas-phase molecules. We also show how the strong nanosecond laser pulse used for adiabatically laser-aligning the molecules influences the measured electron and ion spectra and angular distributions, and discuss how this may affect the outcome of future time-resolved photoelectron diffraction experiments. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1407.7782v1-abstract-full').style.display = 'none'; document.getElementById('1407.7782v1-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, 2014; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2014. </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">24 pages, 10 figures, Faraday Discussions 171</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1403.2553">arXiv:1403.2553</a> <span> [<a href="https://arxiv.org/pdf/1403.2553">pdf</a>, <a href="https://arxiv.org/format/1403.2553">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> </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/10.1039/C4FD00028E">10.1039/C4FD00028E <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Toward atomic resolution diffractive imaging of isolated molecules with x-ray free-electron lasers </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Stern%2C+S">Stephan Stern</a>, <a href="/search/physics?searchtype=author&query=Holmegaard%2C+L">Lotte Holmegaard</a>, <a href="/search/physics?searchtype=author&query=Filsinger%2C+F">Frank Filsinger</a>, <a href="/search/physics?searchtype=author&query=Rouz%C3%A9e%2C+A">Arnaud Rouz茅e</a>, <a href="/search/physics?searchtype=author&query=Rudenko%2C+A">Artem Rudenko</a>, <a href="/search/physics?searchtype=author&query=Johnsson%2C+P">Per Johnsson</a>, <a href="/search/physics?searchtype=author&query=Martin%2C+A+V">Andrew V. Martin</a>, <a href="/search/physics?searchtype=author&query=Barty%2C+A">Anton Barty</a>, <a href="/search/physics?searchtype=author&query=Bostedt%2C+C">Christoph Bostedt</a>, <a href="/search/physics?searchtype=author&query=Bozek%2C+J+D">John D. Bozek</a>, <a href="/search/physics?searchtype=author&query=Coffee%2C+R+N">Ryan N. Coffee</a>, <a href="/search/physics?searchtype=author&query=Epp%2C+S">Sascha Epp</a>, <a href="/search/physics?searchtype=author&query=Erk%2C+B">Benjamin Erk</a>, <a href="/search/physics?searchtype=author&query=Foucar%2C+L">Lutz Foucar</a>, <a href="/search/physics?searchtype=author&query=Hartmann%2C+R">Robert Hartmann</a>, <a href="/search/physics?searchtype=author&query=Kimmel%2C+N">Nils Kimmel</a>, <a href="/search/physics?searchtype=author&query=K%C3%BChnel%2C+K">Kai-Uwe K眉hnel</a>, <a href="/search/physics?searchtype=author&query=Maurer%2C+J">Jochen Maurer</a>, <a href="/search/physics?searchtype=author&query=Messerschmidt%2C+M">Marc Messerschmidt</a>, <a href="/search/physics?searchtype=author&query=Rudek%2C+B">Benedikt Rudek</a>, <a href="/search/physics?searchtype=author&query=Starodub%2C+D+G">Dmitri G. Starodub</a>, <a href="/search/physics?searchtype=author&query=Th%C3%B8gersen%2C+J">Jan Th酶gersen</a>, <a href="/search/physics?searchtype=author&query=Weidenspointner%2C+G">Georg Weidenspointner</a>, <a href="/search/physics?searchtype=author&query=White%2C+T+A">Thomas A. White</a>, <a href="/search/physics?searchtype=author&query=Stapelfeldt%2C+H">Henrik Stapelfeldt</a> , et al. (3 additional authors not shown) </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="1403.2553v1-abstract-short" style="display: inline;"> We give a detailed account of the theoretical analysis and the experimental results of an x-ray-diffraction experiment on quantum-state selected and strongly laser-aligned gas-phase ensembles of the prototypical large asymmetric rotor molecule 2,5-diiodobenzonitrile, performed at the Linac Coherent Light Source [Phys. Rev. Lett. 112, 083002 (2014)]. This experiment is the first step toward coheren… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1403.2553v1-abstract-full').style.display = 'inline'; document.getElementById('1403.2553v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1403.2553v1-abstract-full" style="display: none;"> We give a detailed account of the theoretical analysis and the experimental results of an x-ray-diffraction experiment on quantum-state selected and strongly laser-aligned gas-phase ensembles of the prototypical large asymmetric rotor molecule 2,5-diiodobenzonitrile, performed at the Linac Coherent Light Source [Phys. Rev. Lett. 112, 083002 (2014)]. This experiment is the first step toward coherent diffractive imaging of structures and structural dynamics of isolated molecules at atomic resolution, i. e., picometers and femtoseconds, using x-ray free-electron lasers. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1403.2553v1-abstract-full').style.display = 'none'; document.getElementById('1403.2553v1-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 March, 2014; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2014. </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">submitted to Faraday Discussions 171 "Emerging Photon Technologies for Chemical Dynamics"</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Faraday Discuss., 2014,171, 393-418 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1307.4577">arXiv:1307.4577</a> <span> [<a href="https://arxiv.org/pdf/1307.4577">pdf</a>, <a href="https://arxiv.org/format/1307.4577">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> </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.112.083002">10.1103/PhysRevLett.112.083002 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> X-ray diffraction from isolated and strongly aligned gas-phase molecules with a free-electron laser </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=K%C3%BCpper%2C+J">Jochen K眉pper</a>, <a href="/search/physics?searchtype=author&query=Stern%2C+S">Stephan Stern</a>, <a href="/search/physics?searchtype=author&query=Holmegaard%2C+L">Lotte Holmegaard</a>, <a href="/search/physics?searchtype=author&query=Filsinger%2C+F">Frank Filsinger</a>, <a href="/search/physics?searchtype=author&query=Rouz%C3%A9e%2C+A">Arnaud Rouz茅e</a>, <a href="/search/physics?searchtype=author&query=Rudenko%2C+A">Artem Rudenko</a>, <a href="/search/physics?searchtype=author&query=Johnsson%2C+P">Per Johnsson</a>, <a href="/search/physics?searchtype=author&query=Martin%2C+A+V">Andrew V. Martin</a>, <a href="/search/physics?searchtype=author&query=Adolph%2C+M">Marcus Adolph</a>, <a href="/search/physics?searchtype=author&query=Aquila%2C+A">Andrew Aquila</a>, <a href="/search/physics?searchtype=author&query=Bajt%2C+S">Sa拧a Bajt</a>, <a href="/search/physics?searchtype=author&query=Barty%2C+A">Anton Barty</a>, <a href="/search/physics?searchtype=author&query=Bostedt%2C+C">Christoph Bostedt</a>, <a href="/search/physics?searchtype=author&query=Bozek%2C+J">John Bozek</a>, <a href="/search/physics?searchtype=author&query=Caleman%2C+C">Carl Caleman</a>, <a href="/search/physics?searchtype=author&query=Coffee%2C+R">Ryan Coffee</a>, <a href="/search/physics?searchtype=author&query=Coppola%2C+N">Nicola Coppola</a>, <a href="/search/physics?searchtype=author&query=Delmas%2C+T">Tjark Delmas</a>, <a href="/search/physics?searchtype=author&query=Epp%2C+S">Sascha Epp</a>, <a href="/search/physics?searchtype=author&query=Erk%2C+B">Benjamin Erk</a>, <a href="/search/physics?searchtype=author&query=Foucar%2C+L">Lutz Foucar</a>, <a href="/search/physics?searchtype=author&query=Gorkhover%2C+T">Tais Gorkhover</a>, <a href="/search/physics?searchtype=author&query=Gumprecht%2C+L">Lars Gumprecht</a>, <a href="/search/physics?searchtype=author&query=Hartmann%2C+A">Andreas Hartmann</a>, <a href="/search/physics?searchtype=author&query=Hartmann%2C+R">Robert Hartmann</a> , et al. (30 additional authors not shown) </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="1307.4577v2-abstract-short" style="display: inline;"> We report experimental results on x-ray diffraction of quantum-state-selected and strongly aligned ensembles of the prototypical asymmetric rotor molecule 2,5-diiodobenzonitrile using the Linac Coherent Light Source. The experiments demonstrate first steps toward a new approach to diffractive imaging of distinct structures of individual, isolated gas-phase molecules. We confirm several key ingredi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1307.4577v2-abstract-full').style.display = 'inline'; document.getElementById('1307.4577v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1307.4577v2-abstract-full" style="display: none;"> We report experimental results on x-ray diffraction of quantum-state-selected and strongly aligned ensembles of the prototypical asymmetric rotor molecule 2,5-diiodobenzonitrile using the Linac Coherent Light Source. The experiments demonstrate first steps toward a new approach to diffractive imaging of distinct structures of individual, isolated gas-phase molecules. We confirm several key ingredients of single molecule diffraction experiments: the abilities to detect and count individual scattered x-ray photons in single shot diffraction data, to deliver state-selected, e. g., structural-isomer-selected, ensembles of molecules to the x-ray interaction volume, and to strongly align the scattering molecules. Our approach, using ultrashort x-ray pulses, is suitable to study ultrafast dynamics of isolated molecules. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1307.4577v2-abstract-full').style.display = 'none'; document.getElementById('1307.4577v2-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 January, 2014; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 17 July, 2013; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 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">submitted to PRL</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Lett. 112, 083002 (2014) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1303.1429">arXiv:1303.1429</a> <span> [<a href="https://arxiv.org/pdf/1303.1429">pdf</a>, <a href="https://arxiv.org/ps/1303.1429">ps</a>, <a href="https://arxiv.org/format/1303.1429">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Accelerator Physics">physics.acc-ph</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="Chemical Physics">physics.chem-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.105.083005">10.1103/PhysRevLett.105.083005 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Double core hole production in N2: Beating the Auger clock </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Fang%2C+L">L. Fang</a>, <a href="/search/physics?searchtype=author&query=Hoener%2C+M">M. Hoener</a>, <a href="/search/physics?searchtype=author&query=Gessner%2C+O">O. Gessner</a>, <a href="/search/physics?searchtype=author&query=Tarantelli%2C+F">F. Tarantelli</a>, <a href="/search/physics?searchtype=author&query=Pratt%2C+S+T">S. T. Pratt</a>, <a href="/search/physics?searchtype=author&query=Kornilov%2C+O">O. Kornilov</a>, <a href="/search/physics?searchtype=author&query=Buth%2C+C">C. Buth</a>, <a href="/search/physics?searchtype=author&query=G%C3%BCehr%2C+M">M. G眉ehr</a>, <a href="/search/physics?searchtype=author&query=Kanter%2C+E+P">E. P. Kanter</a>, <a href="/search/physics?searchtype=author&query=Bostedt%2C+C">C. Bostedt</a>, <a href="/search/physics?searchtype=author&query=Bozek%2C+J+D">J. D. Bozek</a>, <a href="/search/physics?searchtype=author&query=Bucksbaum%2C+P+H">P. H. Bucksbaum</a>, <a href="/search/physics?searchtype=author&query=Chen%2C+M">M. Chen</a>, <a href="/search/physics?searchtype=author&query=Coffee%2C+R">R. Coffee</a>, <a href="/search/physics?searchtype=author&query=Cryan%2C+J">J. Cryan</a>, <a href="/search/physics?searchtype=author&query=Glownia%2C+M">M. Glownia</a>, <a href="/search/physics?searchtype=author&query=Kukk%2C+E">E. Kukk</a>, <a href="/search/physics?searchtype=author&query=Leone%2C+S+R">S. R. Leone</a>, <a href="/search/physics?searchtype=author&query=Berrah%2C+N">N. Berrah</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="1303.1429v1-abstract-short" style="display: inline;"> We investigate the creation of double K-shell holes in N2 molecules via sequential absorption of two photons on a timescale shorter than the core-hole lifetime by using intense x-ray pulses from the Linac Coherent Light Source free electron laser. The production and decay of these states is characterized by photoelectron spectroscopy and Auger electron spectroscopy. In molecules, two types of doub… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1303.1429v1-abstract-full').style.display = 'inline'; document.getElementById('1303.1429v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1303.1429v1-abstract-full" style="display: none;"> We investigate the creation of double K-shell holes in N2 molecules via sequential absorption of two photons on a timescale shorter than the core-hole lifetime by using intense x-ray pulses from the Linac Coherent Light Source free electron laser. The production and decay of these states is characterized by photoelectron spectroscopy and Auger electron spectroscopy. In molecules, two types of double core holes are expected, the first with two core holes on the same N atom, and the second with one core hole on each N atom. We report the first direct observations of the former type of core hole in a molecule, in good agreement with theory, and provide an experimental upper bound for the relative contribution of the latter type. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1303.1429v1-abstract-full').style.display = 'none'; document.getElementById('1303.1429v1-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, 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">5 pages, 3 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> PRL 105, 083005 (2010) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1301.6459">arXiv:1301.6459</a> <span> [<a href="https://arxiv.org/pdf/1301.6459">pdf</a>, <a href="https://arxiv.org/ps/1301.6459">ps</a>, <a href="https://arxiv.org/format/1301.6459">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Accelerator Physics">physics.acc-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.109.263001">10.1103/PhysRevLett.109.263001 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Multiphoton Ionization as a clock to Reveal Molecular Dynamics with Intense Short X-ray Free Electron Laser Pulses </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Fang%2C+L">L. Fang</a>, <a href="/search/physics?searchtype=author&query=Osipov%2C+T">T. Osipov</a>, <a href="/search/physics?searchtype=author&query=Murphy%2C+B">B. Murphy</a>, <a href="/search/physics?searchtype=author&query=Tarantelli%2C+F">F. Tarantelli</a>, <a href="/search/physics?searchtype=author&query=Kukk%2C+E">E. Kukk</a>, <a href="/search/physics?searchtype=author&query=Cryan%2C+J+P">J. P. Cryan</a>, <a href="/search/physics?searchtype=author&query=Glownia%2C+M">M. Glownia</a>, <a href="/search/physics?searchtype=author&query=Bucksbaum%2C+P+H">P. H. Bucksbaum</a>, <a href="/search/physics?searchtype=author&query=Coffee%2C+R+N">R. N. Coffee</a>, <a href="/search/physics?searchtype=author&query=Chen%2C+M">M. Chen</a>, <a href="/search/physics?searchtype=author&query=Buth%2C+C">C. Buth</a>, <a href="/search/physics?searchtype=author&query=Berrah%2C+N">N. Berrah</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="1301.6459v3-abstract-short" style="display: inline;"> We investigate molecular dynamics of multiple ionization in N2 through multiple core-level photoabsorption and subsequent Auger decay processes induced by intense, short X-ray free electron laser pulses. The timing dynamics of the photoabsorption and dissociation processes is mapped onto the kinetic energy of the fragments. Measurements of the latter allow us to map out the average internuclear se… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1301.6459v3-abstract-full').style.display = 'inline'; document.getElementById('1301.6459v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1301.6459v3-abstract-full" style="display: none;"> We investigate molecular dynamics of multiple ionization in N2 through multiple core-level photoabsorption and subsequent Auger decay processes induced by intense, short X-ray free electron laser pulses. The timing dynamics of the photoabsorption and dissociation processes is mapped onto the kinetic energy of the fragments. Measurements of the latter allow us to map out the average internuclear separation for every molecular photoionization sequence step and obtain the average time interval between the photoabsorption events. Using multiphoton ionization as a tool of multiple-pulse pump-probe scheme, we demonstrate the modification of the ionization dynamics as we vary the x-ray laser pulse duration. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1301.6459v3-abstract-full').style.display = 'none'; document.getElementById('1301.6459v3-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, 2013; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 28 January, 2013; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 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">9 pages, 4 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Report number:</span> 1301.6459v1 </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> PRL 109, 263001 (2012) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1301.3104">arXiv:1301.3104</a> <span> [<a href="https://arxiv.org/pdf/1301.3104">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Chemical Physics">physics.chem-ph</span> </div> </div> <p class="title is-5 mathjax"> Delayed Ultrafast X-ray Auger Probing (DUXAP) of Nucleobase Ultraviolet Photoprotection </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=McFarland%2C+B+K">B. K. McFarland</a>, <a href="/search/physics?searchtype=author&query=Farrell%2C+J+P">J. P. Farrell</a>, <a href="/search/physics?searchtype=author&query=Miyabe%2C+S">S. Miyabe</a>, <a href="/search/physics?searchtype=author&query=Tarantelli%2C+F">F. Tarantelli</a>, <a href="/search/physics?searchtype=author&query=Aguilar%2C+A">A. Aguilar</a>, <a href="/search/physics?searchtype=author&query=Berrah%2C+N">N. Berrah</a>, <a href="/search/physics?searchtype=author&query=Bostedt%2C+C">C. Bostedt</a>, <a href="/search/physics?searchtype=author&query=Bozek%2C+J">J. Bozek</a>, <a href="/search/physics?searchtype=author&query=Bucksbaum%2C+P+H">P. H. Bucksbaum</a>, <a href="/search/physics?searchtype=author&query=Castagna%2C+J+C">J. C. Castagna</a>, <a href="/search/physics?searchtype=author&query=Coffee%2C+R">R. Coffee</a>, <a href="/search/physics?searchtype=author&query=Cryan%2C+J">J. Cryan</a>, <a href="/search/physics?searchtype=author&query=Fang%2C+L">L. Fang</a>, <a href="/search/physics?searchtype=author&query=Feifel%2C+R">R. Feifel</a>, <a href="/search/physics?searchtype=author&query=Gaffney%2C+K">K. Gaffney</a>, <a href="/search/physics?searchtype=author&query=Glownia%2C+J">J. Glownia</a>, <a href="/search/physics?searchtype=author&query=Martinez%2C+T">T. Martinez</a>, <a href="/search/physics?searchtype=author&query=Mucke%2C+M">M. Mucke</a>, <a href="/search/physics?searchtype=author&query=Murphy%2C+B">B. Murphy</a>, <a href="/search/physics?searchtype=author&query=Natan%2C+A">A. Natan</a>, <a href="/search/physics?searchtype=author&query=Osipov%2C+T">T. Osipov</a>, <a href="/search/physics?searchtype=author&query=Petrovic%2C+V+.">V . Petrovic</a>, <a href="/search/physics?searchtype=author&query=Schorb%2C+S">S. Schorb</a>, <a href="/search/physics?searchtype=author&query=Schultz%2C+T">Th. Schultz</a>, <a href="/search/physics?searchtype=author&query=Spector%2C+L">L. Spector</a> , et al. (6 additional authors not shown) </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="1301.3104v1-abstract-short" style="display: inline;"> We present a new method for ultrafast spectroscopy of molecular photoexcited dynamics. The technique uses a pair of femtosecond pulses: a photoexcitation pulse initiating excited state dynamics followed by a soft x-ray (SXR) probe pulse that core ionizes certain atoms inside the molecule. We observe the Auger decay of the core hole as a function of delay between the photoexcitation and SXR pulses.… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1301.3104v1-abstract-full').style.display = 'inline'; document.getElementById('1301.3104v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1301.3104v1-abstract-full" style="display: none;"> We present a new method for ultrafast spectroscopy of molecular photoexcited dynamics. The technique uses a pair of femtosecond pulses: a photoexcitation pulse initiating excited state dynamics followed by a soft x-ray (SXR) probe pulse that core ionizes certain atoms inside the molecule. We observe the Auger decay of the core hole as a function of delay between the photoexcitation and SXR pulses. The core hole decay is particularly sensitive to the local valence electrons near the core and shows new types of propensity rules, compared to dipole selection rules in SXR absorption or emission spectroscopy. We apply the delayed ultrafast x-ray Auger probing (DUXAP) method to the specific problem of nucleobase photoprotection to demonstrate its potential. The ultraviolet photoexcited 蟺蟺* states of nucleobases are prone to chemical reactions with neighboring bases. To avoid this, the single molecules funnel the 蟺蟺* population to lower lying electronic states on an ultrafast timescale under violation of the Born-Oppenheimer approximation. The new type of propensity rule, which is confirmed by Auger decay simulations, allows us to have increased sensitivity on the direct relaxation from the 蟺蟺* state to the vibrationally hot electronic ground state. For the nucleobase thymine, we measure a decay constant of 300 fs in agreement with previous quantum chemical simulations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1301.3104v1-abstract-full').style.display = 'none'; document.getElementById('1301.3104v1-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 January, 2013; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2013. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1201.1896">arXiv:1201.1896</a> <span> [<a href="https://arxiv.org/pdf/1201.1896">pdf</a>, <a href="https://arxiv.org/ps/1201.1896">ps</a>, <a href="https://arxiv.org/format/1201.1896">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Chemical Physics">physics.chem-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/10.1063/1.4722756">10.1063/1.4722756 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Ultrafast absorption of intense x rays by nitrogen molecules </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Buth%2C+C">Christian Buth</a>, <a href="/search/physics?searchtype=author&query=Liu%2C+J">Ji-Cai Liu</a>, <a href="/search/physics?searchtype=author&query=Chen%2C+M+H">Mau Hsiung Chen</a>, <a href="/search/physics?searchtype=author&query=Cryan%2C+J+P">James P. Cryan</a>, <a href="/search/physics?searchtype=author&query=Fang%2C+L">Li Fang</a>, <a href="/search/physics?searchtype=author&query=Glownia%2C+J+M">James M. Glownia</a>, <a href="/search/physics?searchtype=author&query=Hoener%2C+M">Matthias Hoener</a>, <a href="/search/physics?searchtype=author&query=Coffee%2C+R+N">Ryan N. Coffee</a>, <a href="/search/physics?searchtype=author&query=Berrah%2C+N">Nora Berrah</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="1201.1896v2-abstract-short" style="display: inline;"> We devise a theoretical description for the response of nitrogen molecules (N2) to ultrashort and intense x rays from the free electron laser (FEL) Linac Coherent Light Source (LCLS). We set out from a rate-equation description for the x-ray absorption by a nitrogen atom. The equations are formulated using all one-x-ray-photon absorption cross sections and the Auger and radiative decay widths of m… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1201.1896v2-abstract-full').style.display = 'inline'; document.getElementById('1201.1896v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1201.1896v2-abstract-full" style="display: none;"> We devise a theoretical description for the response of nitrogen molecules (N2) to ultrashort and intense x rays from the free electron laser (FEL) Linac Coherent Light Source (LCLS). We set out from a rate-equation description for the x-ray absorption by a nitrogen atom. The equations are formulated using all one-x-ray-photon absorption cross sections and the Auger and radiative decay widths of multiply-ionized nitrogen atoms. Cross sections are obtained with a one-electron theory and decay widths are determined from ab initio computations using the Dirac-Hartree-Slater (DHS) method. We also calculate all binding and transition energies of nitrogen atoms in all charge states with the DHS method as the difference of two self-consistent field calculations (Delta SCF method). To describe the interaction with N2, a detailed investigation of intense x-ray-induced ionization and molecular fragmentation are carried out. As a figure of merit, we calculate ion yields and the average charge state measured in recent experiments at the LCLS. We use a series of phenomenological models of increasing sophistication to unravel the mechanisms of the interaction of x rays with N2: a single atom, a symmetric-sharing model, and a fragmentation-matrix model are developed. The role of the formation and decay of single and double core holes, the metastable states of N_2^2+, and molecular fragmentation are explained. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1201.1896v2-abstract-full').style.display = 'none'; document.getElementById('1201.1896v2-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 June, 2012; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 9 January, 2012; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 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">16 pages, 6 figures, 2 tables, RevTeX4.1, supporting materials in the Data Conservancy, revised</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> J. Chem. Phys. 136, 214310 (2012) </p> </li> </ol> <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" aria-label="Secondary">  <div class="column"> <div class="columns"> <div class="column"> <ul class="nav-spaced"> <li><a href="https://info.arxiv.org/about">About</a></li> <li><a href="https://info.arxiv.org/help">Help</a></li> </ul> </div> <div class="column"> <ul class="nav-spaced"> <li> <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" class="icon filter-black" role="presentation"><title>contact arXiv</title><desc>Click here to contact arXiv</desc><path d="M502.3 190.8c3.9-3.1 9.7-.2 9.7 4.7V400c0 26.5-21.5 48-48 48H48c-26.5 0-48-21.5-48-48V195.6c0-5 5.7-7.8 9.7-4.7 22.4 17.4 52.1 39.5 154.1 113.6 21.1 15.4 56.7 47.8 92.2 47.6 35.7.3 72-32.8 92.3-47.6 102-74.1 131.6-96.3 154-113.7zM256 320c23.2.4 56.6-29.2 73.4-41.4 132.7-96.3 142.8-104.7 173.4-128.7 5.8-4.5 9.2-11.5 9.2-18.9v-19c0-26.5-21.5-48-48-48H48C21.5 64 0 85.5 0 112v19c0 7.4 3.4 14.3 9.2 18.9 30.6 23.9 40.7 32.4 173.4 128.7 16.8 12.2 50.2 41.8 73.4 41.4z"/></svg> <a href="https://info.arxiv.org/help/contact.html"> Contact</a> </li> <li> <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" class="icon filter-black" role="presentation"><title>subscribe to arXiv mailings</title><desc>Click here to subscribe</desc><path d="M476 3.2L12.5 270.6c-18.1 10.4-15.8 35.6 2.2 43.2L121 358.4l287.3-253.2c5.5-4.9 13.3 2.6 8.6 8.3L176 407v80.5c0 23.6 28.5 32.9 42.5 15.8L282 426l124.6 52.2c14.2 6 30.4-2.9 33-18.2l72-432C515 7.8 493.3-6.8 476 3.2z"/></svg> <a href="https://info.arxiv.org/help/subscribe"> Subscribe</a> </li> </ul> </div> </div> </div>   <div class="column"> <div class="columns"> <div class="column"> <ul class="nav-spaced"> <li><a href="https://info.arxiv.org/help/license/index.html">Copyright</a></li> <li><a href="https://info.arxiv.org/help/policies/privacy_policy.html">Privacy Policy</a></li> </ul> </div> <div class="column sorry-app-links"> <ul class="nav-spaced"> <li><a href="https://info.arxiv.org/help/web_accessibility.html">Web Accessibility Assistance</a></li> <li> <p class="help"> <a class="a11y-main-link" href="https://status.arxiv.org" target="_blank">arXiv Operational Status <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 256 512" class="icon filter-dark_grey" role="presentation"><path d="M224.3 273l-136 136c-9.4 9.4-24.6 9.4-33.9 0l-22.6-22.6c-9.4-9.4-9.4-24.6 0-33.9l96.4-96.4-96.4-96.4c-9.4-9.4-9.4-24.6 0-33.9L54.3 103c9.4-9.4 24.6-9.4 33.9 0l136 136c9.5 9.4 9.5 24.6.1 34z"/></svg></a><br> Get status notifications via <a class="is-link" href="https://subscribe.sorryapp.com/24846f03/email/new" target="_blank"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" class="icon filter-black" role="presentation"><path d="M502.3 190.8c3.9-3.1 9.7-.2 9.7 4.7V400c0 26.5-21.5 48-48 48H48c-26.5 0-48-21.5-48-48V195.6c0-5 5.7-7.8 9.7-4.7 22.4 17.4 52.1 39.5 154.1 113.6 21.1 15.4 56.7 47.8 92.2 47.6 35.7.3 72-32.8 92.3-47.6 102-74.1 131.6-96.3 154-113.7zM256 320c23.2.4 56.6-29.2 73.4-41.4 132.7-96.3 142.8-104.7 173.4-128.7 5.8-4.5 9.2-11.5 9.2-18.9v-19c0-26.5-21.5-48-48-48H48C21.5 64 0 85.5 0 112v19c0 7.4 3.4 14.3 9.2 18.9 30.6 23.9 40.7 32.4 173.4 128.7 16.8 12.2 50.2 41.8 73.4 41.4z"/></svg>email</a> or <a class="is-link" href="https://subscribe.sorryapp.com/24846f03/slack/new" target="_blank"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 448 512" class="icon filter-black" role="presentation"><path d="M94.12 315.1c0 25.9-21.16 47.06-47.06 47.06S0 341 0 315.1c0-25.9 21.16-47.06 47.06-47.06h47.06v47.06zm23.72 0c0-25.9 21.16-47.06 47.06-47.06s47.06 21.16 47.06 47.06v117.84c0 25.9-21.16 47.06-47.06 47.06s-47.06-21.16-47.06-47.06V315.1zm47.06-188.98c-25.9 0-47.06-21.16-47.06-47.06S139 32 164.9 32s47.06 21.16 47.06 47.06v47.06H164.9zm0 23.72c25.9 0 47.06 21.16 47.06 47.06s-21.16 47.06-47.06 47.06H47.06C21.16 243.96 0 222.8 0 196.9s21.16-47.06 47.06-47.06H164.9zm188.98 47.06c0-25.9 21.16-47.06 47.06-47.06 25.9 0 47.06 21.16 47.06 47.06s-21.16 47.06-47.06 47.06h-47.06V196.9zm-23.72 0c0 25.9-21.16 47.06-47.06 47.06-25.9 0-47.06-21.16-47.06-47.06V79.06c0-25.9 21.16-47.06 47.06-47.06 25.9 0 47.06 21.16 47.06 47.06V196.9zM283.1 385.88c25.9 0 47.06 21.16 47.06 47.06 0 25.9-21.16 47.06-47.06 47.06-25.9 0-47.06-21.16-47.06-47.06v-47.06h47.06zm0-23.72c-25.9 0-47.06-21.16-47.06-47.06 0-25.9 21.16-47.06 47.06-47.06h117.84c25.9 0 47.06 21.16 47.06 47.06 0 25.9-21.16 47.06-47.06 47.06H283.1z"/></svg>slack</a> </p> </li> </ul> </div> </div> </div>  </div> </footer> <script src="https://static.arxiv.org/static/base/1.0.0a5/js/member_acknowledgement.js"></script> </body> </html>

CINXE.COM

Search | arXiv e-print repository