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arXiv · 2509.10107

A Momentum-Resolved X-ray Thomson Scattering Benchmark of Electronic-Response Models in Warm Dense Aluminium

Dmitrii S. Bespalov·Ulf Zastrau·Zhandos A. Moldabekov·Thomas Gawne·Tobias Dornheim·Moyassar Meshhal·Alexis Amouretti·Michal Andrzejewski·Karen Appel·Carsten Baehtz·Erik Brambrink·Khachiwan Buakor·Carolina Camarda·David Chin·Gilbert Collins·Céline Crépeisson·Adrien Descamps·Jon Eggert·Luke Fletcher·Alessandro Forte·Gianluca Gregori·Marion Harmand·Oliver S. Humphries·Hauke Höppner·Jonas Kuhlke·William Lynn·Julian Lütgert·Masruri Masruri·Emma M. McBride·Ryan Stewart McWilliams·Alan Augusto Sanjuan Mora·Jean-Paul Naedler·Paul Neumayer·Charlotte Palmer·Alexander Pelka·Lea Pennacchioni·Calum Prestwood·Natalia A. Pukhareva·Chongbing Qu·Divyanshu Ranjan·Ronald Redmer·Michael Roper·Christoph Sahle·Samuel Schumacher·Jan-Patrick Schwinkendorf·Melanie J. Sieber·Madison Singleton·Ethan Smith·Christian Sternemann·Thomas Stevens·Michael Stevenson·Cornelius Strohm·Minxue Tang·Monika Toncian·Toma Toncian·Thomas Tschentscher·Sam M. Vinko·Justin S. Wark·Max Wilke·Dominik Kraus·Thomas R. Preston
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Abstract

The robust diagnosis of conditions generated in warm dense matter (WDM) experiments remains a persistent challenge. Here we describe the measurement of shock-compressed aluminium at 50 GPa with angle-resolved femtosecond x-ray Thomson scattering (XRTS) over a wide range of scattering wavevectors at the European XFEL. The measured plasmon dispersion and line shape show that the de facto standard approach for analysing XRTS spectra, based on uniform-electron-gas models, systematically overestimates the resonance energy by up to 8 eV. We present an ab initio approach that agrees within the experimental uncertainty and demonstrates that accounting for shock-induced disorder is critical for interpreting shock-compressed systems, providing evidence that ab initio treatments are required for reliable XRTS inference in warm dense aluminium.

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Dmitrii S. Bespalov, Ulf Zastrau, Zhandos A. Moldabekov, Thomas Gawne, Tobias Dornheim, Moyassar Meshhal, Alexis Amouretti, Michal Andrzejewski, Karen Appel, Carsten Baehtz, Erik Brambrink, Khachiwan Buakor, Carolina Camarda, David Chin, Gilbert Collins, Céline Crépeisson, Adrien Descamps, Jon Eggert, Luke Fletcher, Alessandro Forte, Gianluca Gregori, Marion Harmand, Oliver S. Humphries, Hauke Höppner, Jonas Kuhlke, William Lynn, Julian Lütgert, Masruri Masruri, Emma M. McBride, Ryan Stewart McWilliams, Alan Augusto Sanjuan Mora, Jean-Paul Naedler, Paul Neumayer, Charlotte Palmer, Alexander Pelka, Lea Pennacchioni, Calum Prestwood, Natalia A. Pukhareva, Chongbing Qu, Divyanshu Ranjan, Ronald Redmer, Michael Roper, Christoph Sahle, Samuel Schumacher, Jan-Patrick Schwinkendorf, Melanie J. Sieber, Madison Singleton, Ethan Smith, Christian Sternemann, Thomas Stevens, Michael Stevenson, Cornelius Strohm, Minxue Tang, Monika Toncian, Toma Toncian, Thomas Tschentscher, Sam M. Vinko, Justin S. Wark, Max Wilke, Dominik Kraus, Thomas R. Preston. 2026-05-06. A Momentum-Resolved X-ray Thomson Scattering Benchmark of Electronic-Response Models in Warm Dense Aluminium. https://doi.org/10.1103/86cw-8wm5

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