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1. Cylindrical compression of thin wires by irradiation with a Joule-class short-pulse laser

Author: Alejandro Laso Garcia, Long Yang, Victorien Bouffetier, Karen Appel, Carsten Baehtz, Johannes Hagemann, Hauke Höppner, Oliver Humphries, Thomas Kluge, Mikhail Mishchenko, Motoaki Nakatsutsumi, Alexander Pelka, Thomas R. Preston, Lisa Randolph, Ulf Zastrau, Thomas E. Cowan, Lingen Huang, and Toma Toncian
Subjects: Science
Abstract: Abstract Equation of state measurements at Jovian or stellar conditions are currently conducted by dynamic shock compression driven by multi-kilojoule multi-beam nanosecond-duration lasers. These experiments require precise design of the target and specific tailoring of the spatial and temporal laser profiles to reach the highest pressures. At the same time, the studies are limited by the low repetition rate of the lasers. Here, we show that by the irradiation of a thin wire with single-beam Joule-class short-pulse laser, a converging cylindrical shock is generated compressing the wire material to conditions relevant to the above applications. The shockwave was observed using Phase Contrast Imaging employing a hard X-ray Free Electron Laser with unprecedented temporal and spatial sensitivity. The data collected for Cu wires is in agreement with hydrodynamic simulations of an ablative shock launched by highly impulsive and transient resistive heating of the wire surface. The subsequent cylindrical shockwave travels toward the wire axis and is predicted to reach a compression factor of 9 and pressures above 800 Mbar. Simulations for astrophysical relevant materials underline the potential of this compression technique as a new tool for high energy density studies at high repetition rates.
Published: 2024
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2. A von Hámos spectrometer for diamond anvil cell experiments at the High Energy Density Instrument of the European X-ray Free-Electron Laser

Author: Johannes M. Kaa, Zuzana Konôpková, Thomas R. Preston, Valerio Cerantola, Christoph J. Sahle, Mirko Förster, Christian Albers, Lélia Libon, Robin Sakrowski, Lennart Wollenweber, Khachiwan Buakor, Anand Dwivedi, Mikhail Mishchenko, Motoaki Nakatsutsumi, Christian Plückthun, Jan-Patrick Schwinkendorf, Georg Spiekermann, Nicola Thiering, Sylvain Petitgirard, Metin Tolan, Max Wilke, Ulf Zastrau, Karen Appel, and Christian Sternemann
Subjects: x-ray spectroscopy, x-ray diffraction, inelastic x-ray scattering, diamond anvil cell, spectrometers, imaging spectroscopy, x-ray detectors, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798, Crystallography, QD901-999
Abstract: A von Hámos spectrometer has been implemented in the vacuum interaction chamber 1 of the High Energy Density instrument at the European X-ray Free-Electron Laser facility. This setup is dedicated, but not necessarily limited, to X-ray spectroscopy measurements of samples exposed to static compression using a diamond anvil cell. Si and Ge analyser crystals with different orientations are available for this setup, covering the hard X-ray energy regime with a sub-eV energy resolution. The setup was commissioned by measuring various emission spectra of free-standing metal foils and oxide samples in the energy range between 6 and 11 keV as well as low momentum-transfer inelastic X-ray scattering from a diamond sample. Its capabilities to study samples at extreme pressures and temperatures have been demonstrated by measuring the electronic spin-state changes of (Fe0.5Mg0.5)O, contained in a diamond anvil cell and pressurized to 100 GPa, via monitoring the Fe Kβ fluorescence with a set of four Si(531) analyser crystals at close to melting temperatures. The efficiency and signal-to-noise ratio of the spectrometer enables valence-to-core emission signals to be studied and single pulse X-ray emission from samples in a diamond anvil cell to be measured, opening new perspectives for spectroscopy in extreme conditions research.
Published: 2023
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3. A MHz X-ray diffraction set-up for dynamic compression experiments in the diamond anvil cell

Author: Rachel J. Husband, Cornelius Strohm, Karen Appel, Orianna B. Ball, Richard Briggs, Johannes Buchen, Valerio Cerantola, Stella Chariton, Amy L. Coleman, Hyunchae Cynn, Dana Dattelbaum, Anand Dwivedi, Jon H. Eggert, Lars Ehm, William J. Evans, Konstantin Glazyrin, Alexander F. Goncharov, Heinz Graafsma, Alex Howard, Larissa Huston, Trevor M. Hutchinson, Huijeong Hwang, Sony Jacob, Johannes Kaa, Jaeyong Kim, Minseob Kim, Egor Koemets, Zuzana Konôpková, Falko Langenhorst, Torsten Laurus, Xinyang Li, Jona Mainberger, Hauke Marquardt, Emma E. McBride, Christopher McGuire, James D. McHardy, Malcolm I. McMahon, R. Stewart McWilliams, Alba S. J. Méndez, Anshuman Mondal, Guillaume Morard, Earl F. O'Bannon, Christoph Otzen, Charles M. Pépin, Vitali B. Prakapenka, Clemens Prescher, Thomas R. Preston, Ronald Redmer, Michael Roeper, Carmen Sanchez-Valle, Dean Smith, Raymond F. Smith, Daniel Sneed, Sergio Speziale, Tobias Spitzbart, Stephan Stern, Blake T. Sturtevant, Jolanta Sztuk-Dambietz, Peter Talkovski, Nenad Velisavljevic, Cara Vennari, Zhongyan Wu, Choong-Shik Yoo, Ulf Zastrau, Zsolt Jenei, and Hanns-Peter Liermann
Subjects: extreme conditions science, x-ray free-electron lasers, diamond anvil cells, dynamic compression, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798, Crystallography, QD901-999
Abstract: An experimental platform for dynamic diamond anvil cell (dDAC) research has been developed at the High Energy Density (HED) Instrument at the European X-ray Free Electron Laser (European XFEL). Advantage was taken of the high repetition rate of the European XFEL (up to 4.5 MHz) to collect pulse-resolved MHz X-ray diffraction data from samples as they are dynamically compressed at intermediate strain rates (≤103 s−1), where up to 352 diffraction images can be collected from a single pulse train. The set-up employs piezo-driven dDACs capable of compressing samples in ≥340 µs, compatible with the maximum length of the pulse train (550 µs). Results from rapid compression experiments on a wide range of sample systems with different X-ray scattering powers are presented. A maximum compression rate of 87 TPa s−1 was observed during the fast compression of Au, while a strain rate of ∼1100 s−1 was achieved during the rapid compression of N2 at 23 TPa s−1.
Published: 2023
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4. Direct LiF imaging diagnostics on refractive X-ray focusing at the EuXFEL High Energy Density instrument

Author: Sergey Makarov, Mikako Makita, Motoaki Nakatsutsumi, Tatiana Pikuz, Norimasa Ozaki, Thomas R. Preston, Karen Appel, Zuzana Konopkova, Valerio Cerantola, Erik Brambrink, Jan-Patrick Schwinkendorf, Istvan Mohacsi, Tomas Burian, Jaromir Chalupsky, Vera Hajkova, Libor Juha, Vojtech Vozda, Bob Nagler, Ulf Zastrau, and Sergey Pikuz
Subjects: x-ray free-electron lasers, x-ray focusing, x-ray beam characterization, compound refractive lenses, focusing system, lithium fluoride (lif) detector, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798, Crystallography, QD901-999
Abstract: The application of fluorescent crystal media in wide-range X-ray detectors provides an opportunity to directly image the spatial distribution of ultra-intense X-ray beams including investigation of the focal spot of free-electron lasers. Here the capabilities of the micro- and nano-focusing X-ray refractive optics available at the High Energy Density instrument of the European XFEL are reported, as measured in situ by means of a LiF fluorescent detector placed into and around the beam caustic. The intensity distribution of the beam focused down to several hundred nanometers was imaged at 9 keV photon energy. A deviation from the parabolic surface in a stack of nanofocusing Be compound refractive lenses (CRLs) was found to affect the resulting intensity distribution within the beam. Comparison of experimental patterns in the far field with patterns calculated for different CRL lens imperfections allowed the overall inhomogeneity in the CRL stack to be estimated. The precise determination of the focal spot size and shape on a sub-micrometer level is essential for a number of high energy density studies requiring either a pin-size backlighting spot or extreme intensities for X-ray heating.
Published: 2023
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5. Structural and electron spin state changes in an x-ray heated iron carbonate system at the Earth's lower mantle pressures

Author: Johannes M. Kaa, Christian Sternemann, Karen Appel, Valerio Cerantola, Thomas R. Preston, Christian Albers, Mirko Elbers, Lélia Libon, Mikako Makita, Alexander Pelka, Sylvain Petitgirard, Christian Plückthun, Vladimir Roddatis, Christoph J. Sahle, Georg Spiekermann, Christian Schmidt, Anja Schreiber, Robin Sakrowski, Metin Tolan, Max Wilke, Ulf Zastrau, and Zuzana Konôpková
Subjects: Physics, QC1-999
Abstract: The determination of the spin state of iron-bearing compounds at high pressure and temperature is crucial for our understanding of chemical and physical properties of the deep Earth. Studies on the relationship between the coordination of iron and its electronic spin structure in iron-bearing oxides, silicates, carbonates, iron alloys, and other minerals found in the Earth's mantle and core are scarce because of the technical challenges to simultaneously probe the sample at high pressures and temperatures. We used the unique properties of a pulsed and highly brilliant x-ray free electron laser (XFEL) beam at the High Energy Density (HED) instrument of the European XFEL to x-ray heat and probe samples contained in a diamond anvil cell. We heated and probed with the same x-ray pulse train and simultaneously measured x-ray emission and x-ray diffraction of an FeCO_{3} sample at a pressure of 51 GPa with up to melting temperatures. We collected spin state sensitive Fe Kβ_{1,3} fluorescence spectra and detected the sample's structural changes via diffraction, observing the inverse volume collapse across the spin transition. During x-ray heating, the carbonate transforms into orthorhombic Fe_{4}C_{3}O_{12} and iron oxides. Incipient melting was also observed. This approach to collect information about the electronic state and structural changes from samples contained in a diamond anvil cell at melting temperatures and above will considerably improve our understanding of the structure and dynamics of planetary and exoplanetary interiors.
Published: 2022
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6. Towards perfectly linearly polarized x-rays

Author: Kai S. Schulze, Benjamin Grabiger, Robert Loetzsch, Berit Marx-Glowna, Annika T. Schmitt, Alejandro Laso Garcia, Willi Hippler, Lingen Huang, Felix Karbstein, Zuzana Konôpková, Hans-Peter Schlenvoigt, Jan-Patrick Schwinkendorf, Cornelius Strohm, Toma Toncian, Ingo Uschmann, Hans-Christian Wille, Ulf Zastrau, Ralf Röhlsberger, Thomas Stöhlker, Thomas E. Cowan, and Gerhard G. Paulus
Subjects: Physics, QC1-999
Abstract: In recent years, high-precision x-ray polarimeters have become a key method for the investigation of fundamental physical questions from solid-state physics to quantum optics. Here, we report on the verification of a polarization purity of better than 8×10^{−11} at an x-ray free-electron laser, which implies a suppression of the incoming photons to the noise level in the crossed polarizer setting. This purity provides exceptional sensitivity to tiny polarization changes and offers intriguing perspectives for fundamental tests of quantum electrodynamics.
Published: 2022
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7. Photon Beam Transport and Scientific Instruments at the European XFEL

Author: Thomas Tschentscher, Christian Bressler, Jan Grünert, Anders Madsen, Adrian P. Mancuso, Michael Meyer, Andreas Scherz, Harald Sinn, and Ulf Zastrau
Subjects: free-electron lasers, average brilliance, peak brilliance, photon diagnostics, X-ray optics, femtosecond time resolution, coherent X-ray diffraction imaging, ultrafast diffraction, ultrafast absorption and emission spectroscopy, non-linear X-ray processes, Technology, Engineering (General). Civil engineering (General), TA1-2040, Biology (General), QH301-705.5, Physics, QC1-999, Chemistry, QD1-999
Abstract: European XFEL is a free-electron laser (FEL) user facility providing soft and hard X-ray FEL radiation to initially six scientific instruments. Starting user operation in fall 2017 European XFEL will provide new research opportunities to users from science domains as diverse as physics, chemistry, geo- and planetary sciences, materials sciences or biology. The unique feature of European XFEL is the provision of high average brilliance in the soft and hard X-ray regime, combined with the pulse properties of FEL radiation of extreme peak intensities, femtosecond pulse duration and high degree of coherence. The high average brilliance is achieved through acceleration of up to 27,000 electron bunches per second by the super-conducting electron accelerator. Enabling the usage of this high average brilliance in user experiments is one of the major instrumentation drivers for European XFEL. The radiation generated by three FEL sources is distributed via long beam transport systems to the experiment hall where the scientific instruments are located side-by-side. The X-ray beam transport systems have been optimized to maintain the unique features of the FEL radiation which will be monitored using build-in photon diagnostics. The six scientific instruments are optimized for specific applications using soft or hard X-ray techniques and include integrated lasers, dedicated sample environment, large area high frame rate detector(s) and computing systems capable of processing large quantities of data.
Published: 2017
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8. Novel experimental setup for megahertz X-ray diffraction in a diamond anvil cell at the High Energy Density (HED) instrument of the European X-ray Free-Electron Laser (EuXFEL)

Author: M. A. Baron, Leora E. Dresselhaus-Marais, Guillaume Morard, A. L. Coleman, Vitali B. Prakapenka, Mungo Frost, Jaeyong Kim, Julien Chantel, Dana M. Dattelbaum, Jon Eggert, Carsten Baehtz, Clemens Prescher, J. Mainberger, Guillaume Fiquet, William J. Evans, Edward J. Pace, A. Pelka, Richard Briggs, C. Strohm, Choong-Shik Yoo, Malcolm McMahon, Orianna B. Ball, P. Talkovski, Sven Toleikis, R. J. Husband, Konstantin Glazyrin, Georg Spiekermann, E. F. O'Bannon, Maxim Bykov, Karen Appel, Hauke Marquardt, Lars Ehm, M. Roeper, A. Schropp, H. Damker, Huijeong Hwang, Ulf Zastrau, Sébastien Merkel, J. D. McHardy, Sergio Speziale, Hanns-Peter Liermann, Falko Langenhorst, Blake T. Sturtevant, Emma McBride, Elena Bykova, Charles Pépin, C. Otzen, Naresh Kujala, Yongjae Lee, Zs. Jenei, Max Wilke, R. S. McWilliams, Ronald Redmer, M. Makita, Alexander F. Goncharov, Nenad Velisavljevic, Carmen Sanchez-Valle, Valerio Cerantola, A. Berghäuser, Hyunchae Cynn, M. Foese, Z. Konopkova, Markus O. Schoelmerich, Jeffrey S. Pigott, Deutsches Elektronen-Synchrotron [Hamburg] (DESY), University of Edinburgh, DAM Île-de-France (DAM/DIF), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Université Paris-Saclay, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Lawrence Livermore National Laboratory (LLNL), Unité Matériaux et Transformations - UMR 8207 (UMET), Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Los Alamos National Laboratory (LANL), Stony Brook University [SUNY] (SBU), State University of New York (SUNY), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), Yonsei University, Hanyang University, Friedrich-Schiller-Universität = Friedrich Schiller University Jena [Jena, Germany], University of Oxford, Institut des Sciences de la Terre (ISTerre), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Gustave Eiffel-Université Grenoble Alpes (UGA), Case Western Reserve University [Cleveland], Consortium for Advanced Radiation Sources, University of Chicago, Institut für Physik [Rostock], Universität Rostock, Westfälische Wilhelms-Universität Münster = University of Münster (WWU), German Research Centre for Geosciences - Helmholtz-Centre Potsdam (GFZ), University of Potsdam = Universität Potsdam, Washington State University (WSU), European Project: 730872,CALIPSOplus, Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centrale Lille Institut (CLIL), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), University of Oxford [Oxford], University of Münster, Universität Potsdam, Université de Lille, CNRS, INRA, ENSCL, Deutsches Elektronen-Synchrotron [Hamburg] [DESY], DAM Île-de-France [DAM/DIF], Helmholtz-Zentrum Dresden-Rossendorf [HZDR], Institut de minéralogie, de physique des matériaux et de cosmochimie [IMPMC], Lawrence Livermore National Laboratory [LLNL], Unité Matériaux et Transformations - UMR 8207 [UMET], Los Alamos National Laboratory [LANL], Stony Brook University [SUNY] [SBU], Institut des Sciences de la Terre [ISTerre], German Research Centre for Geosciences - Helmholtz-Centre Potsdam [GFZ], Washington State University [WSU], Liermann, H, Konôpková, Z, Appel, K, Prescher, C, Schropp, A, Cerantola, V, Husband, R, Mchardy, J, Mcmahon, M, Mcwilliams, R, Pépin, C, Mainberger, J, Roeper, M, Berghäuser, A, Damker, H, Talkovski, P, Foese, M, Kujala, N, Ball, O, Baron, M, Briggs, R, Bykov, M, Bykova, E, Chantel, J, Coleman, A, Cynn, H, Dattelbaum, D, Dresselhaus-Marais, L, Eggert, J, Ehm, L, Evans, W, Fiquet, G, Frost, M, Glazyrin, K, Goncharov, A, Hwang, H, Jenei, Z, Kim, J, Langenhorst, F, Lee, Y, Makita, M, Marquardt, H, Mcbride, E, Merkel, S, Morard, G, O'Bannon, E, Otzen, C, Pace, E, Pelka, A, Pigott, J, Prakapenka, V, Redmer, R, Sanchez-Valle, C, Schoelmerich, M, Speziale, S, Spiekermann, G, Sturtevant, B, Toleikis, S, Velisavljevic, N, Wilke, M, Yoo, C, Baehtz, C, Zastrau, U, Strohm, C, Konôpková, Z., 2European X-Ray Free-Electron Laser Facility GmbH, Holzkoppel 4, 22869 Schenefeld, Germany, Appel, K., Prescher, C., 1Photon Sciences, Deutsches Elektronen-Synchrotron (DESY), Notkestraße 85, Hamburg, Germany, Schropp, A., Cerantola, V., Husband, R. J., McHardy, J. D., 3School of Physics and Astronomy, Centre for Science at Extreme Conditions, and SUPA, University of Edinburgh, Peter Guthrie Tait Road, EdinburghEH9 3FD, United Kingdom, McMahon, M. I., Pépin, C. M., 4CEA, DAM, DIF, F-91297 Arpajon, France, Mainberger, J., Roeper, M., Berghäuser, A., 6Helmholtz Zentrum Dresden Rossendorf e.V., 01328 Dresden, Germany, Damker, H., Talkovski, P., Foese, M., Kujala, N., Ball, O. B., Baron, M. A., 7Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), Sorbonne Université, UMR CNRS 7590, Musée National d'Histoire Naturelle, 4 Place Jussieu, Paris, France, Briggs, R., 8Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550, USA, Bykov, M., 9Carnegie Science, Earth and Planets Laboratory, 5241 Broad Branch Road NW, Washington, DC 20015, USA, Bykova, E., Chantel, J., 10Université de Lille, CNRS, INRAE, Centrale Lille, UMR 8207 – UMET – Unité Matériaux et Transformations, F-59000 Lille, France, Coleman, A. L., Cynn, H., Dattelbaum, D., 11Los Alamos National Laboratory, Los Alamos, NM 87545, USA, Dresselhaus-Marais, L. E., Eggert, J. H., Ehm, L., 12Mineral Physics Institute, Stony Brook University, Stony Brook, NY 11794, USA, Evans, W. J., Fiquet, G., Frost, M., 13SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA, Glazyrin, K., Goncharov, A. F., Hwang, H., 14Department of Earth System Sciences, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea, Jenei, Zs., Kim, J.-Y., 15Department of Physics, Research Institute for High Pressure, Hanyang University, 222 Wangsimni-ro, Seoul 04763, Republic of Korea, Langenhorst, F., 16Institute of Geosciences, Friedrich Schiller University Jena, Carl-Zeiss-Promenade 10, 07745 Jena, Germany, Lee, Y., Makita, M., Marquardt, H., 17Department of Earth Sciences, University of Oxford, South Parks Road, OxfordOX1 3AN, United Kingdom, McBride, E. E., Merkel, S., Morard, G., O'Bannon, E. F., Otzen, C., Pace, E. J., Pelka, A., Pigott, J. S., Prakapenka, V. B., 20Center for Advanced Radiation Sources, University of Chicago, Chicago, IL 60637, USA, Redmer, R., 21Institut für Physik, Universität Rostock, D-18051 Rostock, Germany, Sanchez-Valle, C., 22Institut für Mineralogie, University of Münster, Münster, Germany, Schoelmerich, M., Speziale, S., 23GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany, Spiekermann, G., 24Institut für Geowissenschaften, Universität Potsdam, Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Germany, Sturtevant, B. T., Toleikis, S., Velisavljevic, N., Wilke, M., Yoo, C.-S., 25Department of Chemistry, Institute of Shock Physics, and Materials Science and Engineering, Washington State University, Pullman, WA 99164, USA, Baehtz, C., Zastrau, U., and Strohm, C.
Subjects: Diffraction, Nuclear and High Energy Physics, Materials science, diamond anvil cells, X‐ray free‐electron lasers, x-ray free electron lasers, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], 02 engineering and technology, 01 natural sciences, Diamond anvil cell, law.invention, Optics, law, 0103 physical sciences, ddc:550, 010306 general physics, Instrumentation, high‐precision X‐ray diffraction, Radiation, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], business.industry, X-ray free-electron lasers, high-precision X-ray diffraction, finite element modeling, Detector, Free-electron laser, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Laser, Research Papers, Beamline, high precision x-ray diffraction, X-ray crystallography, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], X-ray free-electron laser, Vacuum chamber, 0210 nano-technology, business, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], [SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy
Abstract: Journal of synchrotron radiation 28(3), 688 - 706 (2021). doi:10.1107/S1600577521002551, The high-precision X-ray diffraction setup for work with diamond anvil cells (DACs) in interaction chamber 2 (IC2) of the High Energy Density instrument of the European X-ray Free-Electron Laser is described. This includes beamline optics, sample positioning and detector systems located in the multipurpose vacuum chamber. Concepts for pump–probe X-ray diffraction experiments in the DAC are described and their implementation demonstrated during the First User Community Assisted Commissioning experiment. X-ray heating and diffraction of Bi under pressure, obtained using 20 fs X-ray pulses at 17.8 keV and 2.2 MHz repetition, is illustrated through splitting of diffraction peaks, and interpreted employing finite element modeling of the sample chamber in the DAC., Published by Wiley-Blackwell, [S.l.]
Published: 2021
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9. X-ray Free Electron Laser-Induced Synthesis of ϵ-Iron Nitride at High Pressures

Author: Dana Dattlebaum, Alexander F. Goncharov, Thomas Vogt, R. Stewart McWilliams, R. J. Husband, Guillaume Morard, Emma McBride, A. L. Coleman, Vitali B. Prakapenka, Jaeyong Kim, Jona Mainberger, Elena Bykova, Jeffrey S. Pigott, Julien Chantel, Zuzana Konôpková, Leora E. Dresselhaus-Marais, Yongjae Lee, E. F. O'Bannon, Georg Spiekermann, A. Pelka, Karen Appel, Jon Eggert, Nenad Velisavljevic, Christoph Otzen, Richard Briggs, Clemens Prescher, Konstantin Glazyrin, Guillaume Fiquet, Mungo Frost, M. A. Baron, Edward J. Pace, James D. McHardy, Ulf Zastrau, Hyunchae Cynn, Max Wilke, C. Strohm, Lars Ehm, Taehyun Kim, Hauke Marquardt, Hanns-Peter Liermann, Valerio Cerantola, Charles Pépin, Sébastien Merkel, Blake T. Sturtevant, Malcolm McMahon, Orianna B. Ball, Ronald Redmer, M. Makita, Choong-Shik Yoo, Zsolt Jenei, Maxim Bykov, Carsten Baehtz, Sergio Speziale, Huijeong Hwang, William J. Evans, Hwang, H, Kim, T, Cynn, H, Vogt, T, Husband, R, Appel, K, Baehtz, C, Ball, O, Baron, M, Briggs, R, Bykov, M, Bykova, E, Cerantola, V, Chantel, J, Coleman, A, Dattlebaum, D, Dresselhaus-Marais, L, Eggert, J, Ehm, L, Evans, W, Fiquet, G, Frost, M, Glazyrin, K, Goncharov, A, Jenei, Z, Kim, J, Konôpková, Z, Mainberger, J, Makita, M, Marquardt, H, Mcbride, E, Mchardy, J, Merkel, S, Morard, G, O'Bannon, E, Otzen, C, Pace, E, Pelka, A, Pépin, C, Pigott, J, Prakapenka, V, Prescher, C, Redmer, R, Speziale, S, Spiekermann, G, Strohm, C, Sturtevant, B, Velisavljevic, N, Wilke, M, Yoo, C, Zastrau, U, Liermann, H, Mcmahon, M, Mcwilliams, R, Lee, Y, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), Yonsei University, Lawrence Livermore National Laboratory (LLNL), University of South Carolina [Columbia], Deutsches Elektronen-Synchrotron [Hamburg] (DESY), University of Edinburgh, Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), Carnegie Institution for Science, Unité Matériaux et Transformations - UMR 8207 (UMET), Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Los Alamos National Laboratory (LANL), Stony Brook University [SUNY] (SBU), State University of New York (SUNY), Hanyang University, Department of Earth Sciences [Oxford], University of Oxford, Institut des Sciences de la Terre (ISTerre), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Gustave Eiffel-Université Grenoble Alpes (UGA), DAM Île-de-France (DAM/DIF), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Université Paris-Saclay, Case Western Reserve University [Cleveland], University of Chicago, Institut für Physik [Rostock], Universität Rostock, GeoForschungsZentrum - Helmholtz-Zentrum Potsdam (GFZ), Institut für Geowissenschaften [Potsdam], University of Potsdam = Universität Potsdam, Washington State University (WSU), Carnegie Institution for Science [Washington], Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centrale Lille Institut (CLIL), University of Oxford [Oxford], Universität Potsdam, Université de Lille, CNRS, INRA, ENSCL, Lawrence Livermore National Laboratory [LLNL], Deutsches Elektronen-Synchrotron [Hamburg] [DESY], Institut de minéralogie, de physique des matériaux et de cosmochimie [IMPMC], Unité Matériaux et Transformations - UMR 8207 [UMET], Los Alamos National Laboratory [LANL], Stony Brook University [SUNY] [SBU], Institut des Sciences de la Terre [ISTerre], DAM Île-de-France [DAM/DIF], GeoForschungsZentrum - Helmholtz-Zentrum Potsdam [GFZ], and Washington State University [WSU]
Subjects: Diffraction, Materials science, Solid-gas reaction, X-ray free electron laser, Diamond-anvil cell, Iron, Iron nitride, synthesis, Nitrogen, x-ray heating, Analytical chemistry, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], 02 engineering and technology, Activation energy, 010402 general chemistry, 01 natural sciences, Diamond anvil cell, high temperature, chemistry.chemical_compound, extreme condition, Chemical reactions, X-rays, General Materials Science, ddc:530, Irradiation, Physical and Theoretical Chemistry, iron nitride, ComputingMilieux_MISCELLANEOUS, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], XFEL, X-ray, Free-electron laser, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, high pressure, chemistry, diamond anvil cell, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 0210 nano-technology, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Ultrashort pulse, [SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy
Abstract: The journal of physical chemistry letters 12(12), 3246 - 3252 (2021). doi:10.1021/acs.jpclett.1c00150, The ultrafast synthesis of ε-Fe$_3$N$_{1+x}$ in a diamond-anvil cell (DAC) from Feand N$_2$ under pressure was observed using serial exposures of an X-ray free electron laser (XFEL). When the sample at 5 GPa was irradiated by a pulse train separated by 443 ns, the estimated sample temperature at the delay time was above 1400 K, confirmed by in situ transformation of $α$- to $γ$-iron. Ultimately, the Fe and N$_2$ reacted uniformly throughout the beam path to form Fe$_3$N$_{1.33}$, as deduced from its established equation of state (EOS). We thus demonstrate that the activation energy provided by intense X-ray exposures in an XFEL can be coupled with the source time structure to enable exploration of the time-dependence of reactions under high-pressure conditions., Published by ACS, Washington, DC
Published: 2021
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10. ReLaX: the Helmholtz International Beamline for Extreme Fields high-intensity short-pulse laser driver for relativistic laser–matter interaction and strong-field science using the high energy density instrument at the European X-ray free electron laser facility

Author: Hauke Höppner, A. Pelka, Hans-Peter Schlenvoigt, Michal Smid, Gerd Priebe, Jia Liu, Erik Brambrink, Dominik Möller, M. Toncian, T. R. Preston, Motoaki Nakatsutsumi, T. Toncian, Sebastian Göde, A.-M. Talposi, Thomas Kluge, A. Laso Garcia, J.-P. Schwinkendorf, Ulrich Schramm, M. Makita, C. Bähtz, Ulf Zastrau, S. Di Dio Cafiso, J. Dreyer, Mohamed Hassan, and Thomas E. Cowan
Subjects: Physics, Nuclear and High Energy Physics, business.industry, X-ray, Free-electron laser, Short pulse laser, Strong field, Laser, Atomic and Molecular Physics, and Optics, relativistic intensity laser, Electronic, Optical and Magnetic Materials, law.invention, symbols.namesake, Optics, Nuclear Energy and Engineering, Beamline, law, Helmholtz free energy, symbols, Energy density, Sa laser [Ti], X-ray Free Electron Laser, High-intensity laser, business
Abstract: High-energy and high-intensity lasers are essential for pushing the boundaries of science. Their development has allowed leaps forward in basic research areas, including laser–plasma interaction, high-energy density science, metrology, biology and medical technology. The Helmholtz International Beamline for Extreme Fields user consortium contributes and operates two high-peak-power optical lasers using the high energy density instrument at the European X-ray free electron laser (EuXFEL) facility. These lasers will be used to generate transient extreme states of density and temperature to be probed by the X-ray beam. This paper introduces the ReLaX laser, a short-pulse high-intensity Ti:Sa laser system, and discusses its characteristics as available for user experiments. It will also present the first experimental commissioning results validating its successful integration into the EuXFEL infrastructure and viability as a relativistic-intensity laser driver.
Published: 2021

11. High-resolution inelastic x-ray scattering at the high energy density scientific instrument at the European X-Ray Free-Electron Laser

Author: C. Plückthun, Sebastian Göde, Karen Appel, Benjamin K. Ofori-Okai, C. Strohm, Ulf Zastrau, Adrien Descamps, Andrew Comley, Gianluca Gregori, Ingo Uschmann, O. Karnbach, Charlotte Palmer, Lennart Wollenweber, Oliver Humphries, Ronald Redmer, David McGonegle, Justin Wark, Thomas G. White, Luke Fletcher, Jerome B. Hastings, A. Jenei, G. Geloni, Giulio Monaco, Berit Marx-Glowna, Zuzana Konôpková, Jon Eggert, R. Loetzsch, Thomas Tschentscher, Valerio Cerantola, S. H. Glenzer, Dirk O. Gericke, T. R. Preston, Emma McBride, I. Thorpe, Wollenweber, L, Preston, T, Descamps, A, Cerantola, V, Comley, A, Eggert, J, Fletcher, L, Geloni, G, Gericke, D, Glenzer, S, G??de, S, Hastings, J, Humphries, O, Jenei, A, Karnbach, O, Konopkova, Z, Loetzsch, R, Marx-Glowna, B, Mcbride, E, Mcgonegle, D, Monaco, G, Ofori-Okai, B, Palmer, C, Pl??ckthun, C, Redmer, R, Strohm, C, Thorpe, I, Tschentscher, T, Uschmann, I, Wark, J, White, T, Appel, K, Gregori, G, and Zastrau, U
Subjects: Spectrum analyzer, Materials science, Inelastic scattering, 01 natural sciences, monochromator, 010305 fluids & plasmas, law.invention, Optics, law, 0103 physical sciences, Spectral resolution, Instrumentation, Monochromator, 010302 applied physics, business.industry, Scattering, XFEL, Resolution (electron density), Free-electron laser, Laser, ddc:620, business, IXS
Abstract: Review of scientific instruments 92(1), 013101 (2021). doi:10.1063/5.0022886, We introduce a setup to measure high-resolution inelastic x-ray scattering at the High Energy Density scientific instrument at the European X-Ray Free-Electron Laser (XFEL). The setup uses the Si (533) reflection in a channel-cut monochromator and three spherical diced analyzer crystals in near-backscattering geometry to reach a high spectral resolution. An energy resolution of 44 meV is demonstrated for the experimental setup, close to the theoretically achievable minimum resolution. The analyzer crystals and detector are mounted on a curved-rail system, allowing quick and reliable changes in scattering angle without breaking vacuum. The entire setup is designed for operation at 10 Hz, the same repetition rate as the high-power lasers available at the instrument and the fundamental repetition rate of the European XFEL. Among other measurements, it is envisioned that this setup will allow studies of the dynamics of highly transient laser generated states of matter., Published by American Institute of Physics, [S.l.]
Published: 2021
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12. Reply to: Reconsidering X-ray plasmons

Author: Gianluca Gregori, Sebastien LePape, B. Barbrel, Paul Neumayer, Tilo Döppner, Tammy Ma, Marius Millot, J. Welch, Luke Fletcher, Jan Vorberger, Arthur Pak, H. J. Lee, Roger Falcone, David Turnbull, Heinz-Dieter Nuhn, Thomas G. White, Jerome B. Hastings, Carsten Fortmann, Bob Nagler, Philip Heimann, Chi-Chang Kao, Ulf Zastrau, S. H. Glenzer, Mingsheng Wei, D. A. Chapman, Eric Galtier, and Dirk O. Gericke
Subjects: Physics, Condensed matter physics, X-ray, Atomic and Molecular Physics, and Optics, Plasmon, Electronic, Optical and Magnetic Materials
Published: 2020

13. An approach for the measurement of the bulk temperature of single crystal diamond using an X-ray free electron laser

Author: Charlotte Palmer, Luke Fletcher, Giulio Monaco, Siegfried Glenzer, Thomas G. White, C. Plueckthun, Ingo Uschmann, David McGonegle, C. Strohm, Karen Appel, Gianluca Gregori, Sebastian Göde, Jerome B. Hastings, Benjamin K. Ofori-Okai, Ulf Zastrau, Justin Wark, Debbie G. Senesky, Adrien Descamps, O. Karnbach, Oliver Humphries, Jon Eggert, R. Loetzsch, Emma McBride, Amy Lazicki, Valerio Cerantola, Lennart Wollenweber, Dirk O. Gericke, T. R. Preston, Ronald Redmer, Andrew Comley, Descamps, A, Ofori-Okai, B, Appel, K, Cerantola, V, Comley, A, Eggert, J, Fletcher, L, Gericke, D, Göde, S, Humphries, O, Karnbach, O, Lazicki, A, Loetzsch, R, Mcgonegle, D, Palmer, C, Plueckthun, C, Preston, T, Redmer, R, Senesky, D, Strohm, C, Uschmann, I, White, T, Wollenweber, L, Monaco, G, Wark, J, Hastings, J, Zastrau, U, Gregori, G, Glenzer, S, and Mcbride, E
Subjects: 0301 basic medicine, Equation of state, Materials science, Phonon, x-ray heating, Bulk temperature, lcsh:Medicine, Neutron scattering, engineering.material, Temperature measurement, Article, Techniques and instrumentation, 03 medical and health sciences, 0302 clinical medicine, diamond, Condensed-matter physics, lcsh:Science, General, Multidisciplinary, Scattering, XFEL, Physics, lcsh:R, Diamond, Detailed balance, 030104 developmental biology, engineering, lcsh:Q, Atomic physics, ddc:600, 030217 neurology & neurosurgery, IXS
Abstract: Scientific reports 10(1), 14564 (2020). doi:10.1038/s41598-020-71350-x, Published by Macmillan Publishers Limited, part of Springer Nature, [London]
Published: 2020
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14. Design and performance characterisation of the HAPG von Hámos Spectrometer at the High Energy Density Instrument of the European XFEL

Author: Bob Nagler, Katerina Falk, Dominik Kraus, I. Thorpe, Luke Fletcher, P.A. Heimann, M. Zhang, K. Sukharnikov, Michal Smid, T. R. Preston, A. Pelka, J. P. Schwinkendorf, Roger Falcone, O. Karnbach, A. Amouretti, S. Ren, Valerio Cerantola, Marion Harmand, N. J. Hartley, T. Toncian, L. G. Huang, A. Schmidt, Hauke Höppner, Clemens Prescher, Oliver Humphries, Sebastian Göde, D. Chekrygina, H. J. Lee, A. K. Schuster, Erik Brambrink, Eric Galtier, M. Makita, K. Voigt, Karen Appel, Ulf Zastrau, Stefan P. Hau-Riege, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Preston, T, Goede, S, Schwinkendorf, J, Appel, K, Brambrink, E, Cerantola, V, Hoeppner, H, Makita, M, Pelka, A, Prescher, C, Sukharnikov, K, Schmidt, A, Thorpe, I, Toncian, T, Amouretti, A, Chekrygina, D, Falcone, R, Falk, K, Fletcher, L, Galtier, E, Harmand, M, Hartley, N, Hau-Riege, S, Heimann, P, Huang, L, Humphries, O, Karnbach, O, Kraus, D, Lee, H, Nagler, B, Ren, S, Schuster, A, Smid, M, Voigt, K, Zhang, M, and Zastrau, U
Subjects: X-ray detector, [PHYS]Physics [physics], Materials science, Spectrometer, business.industry, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], 01 natural sciences, 010305 fluids & plasmas, Optics, 0103 physical sciences, spectroscopy and imaging, Energy density, Plasma Diagnostics - interferometry, ddc:610, 010306 general physics, business, Instrumentation, Mathematical Physics, ComputingMilieux_MISCELLANEOUS
Abstract: Journal of Instrumentation 15(11), P11033 (2020). doi:10.1088/1748-0221/15/11/P11033, The von Hámos spectrometer setup at the HED instrument of the European XFEL is described in detail. The spectrometer is designed to be operated primarily between 5 and 15 keV to complement the operating photon energy range of the HED instrument. Four Highly Annealed Pyrolitic Graphite (HAPG) crystals are characterised with thicknesses of 40 μm or 100 μm and radius-of-curvature 50 mm or 80 mm, in conjunction with either an ePix100 or Jungfrau detector. The achieved resolution with the 50 mm crystals, operated between 6.5 and 9 keV, matches that reported previously: ~8 eV for a thickness of 40 μm, whereas, with an 80 mm crystal of thickness 40 μm, the resolution exceeds that expected. Namely, a resolution of 2 eV is demonstrated between 5–6 keV implying a resolving power of 2800. Therefore, we posit that flatter HAPG crystals, with their high reflectivity and improved resolving power, are a powerful tool for hard x-ray scattering and emission experiments allowing unprecedented measurements of collective scattering in a single shot., Published by Inst. of Physics, London
Published: 2020
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15. Setup for meV-resolution inelastic X-ray scattering measurements and X-ray diffraction at the Matter in Extreme Conditions endstation at the Linac Coherent Light Source

Author: M. Oliver, Stefan Funk, Benjamin K. Ofori-Okai, Eric Galtier, Giulio Monaco, Gianluca Gregori, Maxence Gauthier, Florian Condamine, J. B. Hastings, Luke Fletcher, Siegfried Glenzer, Karen Appel, Bob Nagler, Hae Ja Lee, Thomas G. White, A. Rigby, Ulf Zastrau, C. Schoenwaelder, B. B. L. Witte, Th. Tschentscher, Sebastian Goede, J. B. Kim, Emma McBride, F. Dallari, Chandra Curry, Adrien Descamps, Peihao Sun, Laboratoire pour l'utilisation des lasers intenses (LULI), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Diffraction, Materials science, business.industry, Phonon, Scattering, Resolution (electron density), 02 engineering and technology, Warm dense matter, 021001 nanoscience & nanotechnology, Laser, 01 natural sciences, Linear particle accelerator, law.invention, Optics, law, 0103 physical sciences, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], 010306 general physics, 0210 nano-technology, business, Instrumentation, Monochromator
Abstract: International audience; We describe a setup for performing inelastic X-ray scattering and X-ray diffraction measurements at the Matter in Extreme Conditions (MEC) endstation of the Linac Coherent Light Source. This technique is capable of performing high-, meV-resolution measurements of dynamic ion features in both crystalline and non-crystalline materials. A four-bounce silicon (533) monochromator was used in conjunction with three silicon (533) diced crystal analyzers to provide an energy resolution of ∼50 meV over a range of ∼500 meV in single shot measurements. In addition to the instrument resolution function, we demonstrate the measurement of longitudinal acoustic phonon modes in polycrystalline diamond. Furthermore, this setup may be combined with the high intensity laser drivers available at MEC to create warm dense matter and subsequently measure ion acoustic modes.
Published: 2018
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16. Simulations of ultrafast x–ray laser experiments

Author: Mikhail Yurkov, Liubov Samoylova, Karen Appel, Sergey Yakubov, Beata Ziaja-Motyka, Zoltan Jurek, Robin Santra, Richard Briggs, Motoaki Nakatsutsumi, Chun Hong Yoon, Adrian P. Mancuso, Ulf Zastrau, Michael Bussmann, Alexander Andreev, A. Sharma, Axel Huebl, Alexey Buzmakov, Marco Garten, Evgeny Schneidmiller, N. D. Loh, Carsten Fortmann-Grote, Alexander Grund, Klaus Steiniger, J. Branco, Tschentscher, Thomas, and Patthey, Luc
Subjects: Physics, Photon, business.industry, Scattering, Plasma, Warm dense matter, Laser, 01 natural sciences, 010305 fluids & plasmas, law.invention, X-ray laser, Optics, law, 0103 physical sciences, State of matter, ddc:620, 010306 general physics, business, Ultrashort pulse
Abstract: SPIE Optics + Optoelectronics, Prague, Czech Republic; Proceedings of SPIE 10237, 102370S (2017). doi:10.1117/12.2270552, Simulations of experiments at modern light sources, such as optical laser laboratories, synchrotrons, and free electron lasers, become increasingly important for the successful preparation, execution, and analysis of these experiments investigating ever more complex physical systems, e.g. biomolecules, complex materials, and ultra–short lived states of matter at extreme conditions. We have implemented a platform for complete start–to–end simulations of various types of photon science experiments, tracking the radiation from the source through the beam transport optics to the sample or target under investigation, its interaction with and scattering from the sample, and registration in a photon detector. This tool allows researchers and facility operators to simulate their experiments and instruments under real life conditions, identify promising and unattainable regions of the parameter space and ultimately make better use of valuable beamtime. In this paper, we present an overview about status and future development of the simulation platform and discuss three applications: 1.) Single–particle imaging of biomolecules using x–ray free electron lasers and optimization of x–ray pulse properties, 2.) x–ray scattering diagnostics of hot dense plasmas in high power laser–matter interaction and identification of plasma instabilities, and 3.) x–ray absorption spectroscopy in warm dense matter created by high energy laser–matter interaction and pulse shape optimization for low–isentrope dynamic compression., Published by SPIE, Bellingham, Wash.
Published: 2017
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17. Observations of strong ion-ion correlations in dense plasmas

Author: Arthur Pak, S. H. Glenzer, David Turnbull, Carsten Fortmann, O. L. Landen, Tilo Döppner, Bob Nagler, T Ma, Jan Vorberger, Gianluca Gregori, S. Le Pape, J. B. Hastings, Thomas G. White, Ulf Zastrau, Roger Falcone, Luke Fletcher, D. A. Chapman, Paul Neumayer, K. Wünsch, Eric Galtier, H. J. Lee, and Dirk O. Gericke
Subjects: Physics, Elastic scattering, Photon, Physics::Plasma Physics, Waves in plasmas, Scattering, Plasma diagnostics, Plasma, Electric potential, Atomic physics, Condensed Matter Physics, Ion
Abstract: Using simultaneous spectrally, angularly, and temporally resolved x-ray scattering, we measure the pronounced ion-ion correlation peak in a strongly coupled plasma. Laser-driven shock-compressed aluminum at ∼3× solid density is probed with high-energy photons at 17.9keV created by molybdenum He-α emission in a laser-driven plasma source. The measured elastic scattering feature shows a well-pronounced correlation peak at a wave vector of k=4Å-1. The magnitude of this correlation peak cannot be described by standard plasma theories employing a linear screened Coulomb potential. Advanced models, including a strong short-range repulsion due to the inner structure of the aluminum ions are however in good agreement with the scattering data. These studies have demonstrated a new highly accurate diagnostic technique to directly measure the state of compression and the ion-ion correlations. We have since applied this new method in single-shot wave-number resolved S(k) measurements to characterize the physical properties of dense plasmas. © 2014 AIP Publishing LLC.
Published: 2016
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18. Focal aberrations of large-aperture HOPG von-Hamos x-ray spectrometers

Author: H. J. Lee, C. R. D. Brown, Gianluca Gregori, E. Förster, S Toleikis, Ulf Zastrau, O. Wehrhan, Heike Marschner, Siegfried Glenzer, and Tilo Döppner
Subjects: Materials science, Aperture, business.industry, Radius of curvature (optics), Crystal, Optics, Cardinal point, Highly oriented pyrolytic graphite, Halo, Crystallite, business, Focus (optics), Instrumentation, Mathematical Physics
Abstract: Focal aberrations of large-aperture highly oriented pyrolytic graphite (HOPG) crystals in von-Hàmos geometry are investigated by experimental and computational methods. A mosaic HOPG crystal film of 100 μm thickness diffracts 8 keV x-rays. This thickness is smaller than the absorption depth of the symmetric 004-reflection, which amounts to 257 μm. Cylindrically bent crystals with 110mm radius of curvature and up to 100 mm collection width produce a X-shaped halo around the focus. This feature vanishes when the collection aperture is reduced, but axial spectral profiles show that the resolution is not affected. X-ray topography reveals significant inhomogeneous crystallite domains of 2±1mm diameter along the entire crystal. Rocking curves shift by about ±20arcmin between domains, while their full width at half-maximum varies between 30 and 50 arcmin. These inhomogeneities are not imprinted at the focal spot, since the monochromatically reflecting area of the crystal is large compared to inhomogeneities. Ray-tracing calculations using a Monte-Carlo-based algorithm developed for mosaic crystals reproduce the X-shaped halo in the focal plane, stemming from the mosaic defocussing in the non-dispersive direction in combination with large apertures. The best achievable resolution is found by analyzing a diversity of rocking curve widths, source sizes and crystal thicknesses for 8 keV x-rays to be ΔE/E ∼ 10-4. Finally a general analytic expression for the shape of the aberration is derived. © 2012 IOP Publishing Ltd and Sissa Medialab srl.
Published: 2016
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19. Resonant Kα spectroscopy of solid-density aluminum plasmas

Author: O. Ciricosta, P.A. Heimann, Libor Juha, Jaromír Chalupský, K. Engelhorn, Tomáš Burian, D. S. Rackstraw, Justin Wark, Diling Zhu, Joshua J. Turner, Hyun-Kyung Chung, C. R. D. Brown, Benny Wu, Sven Toleikis, A. Scherz, Ulf Zastrau, Roger Falcone, Byoung-ick Cho, L. Vysin, William F. Schlotter, Andrew Higginbotham, Nina Rohringer, Catherine Graves, Tianhan Wang, M. Messersmidt, R W Lee, H. J. Lee, Věra Hájková, Bob Nagler, Sam Vinko, C. D. Murphy, Jacek Krzywinski, and Yuan Ping
Subjects: Free electron model, Physics, Photon, Astrophysics::High Energy Astrophysical Phenomena, General Physics and Astronomy, Electron, Ion, Atom, ddc:550, Production (computer science), Absorption (logic), Atomic physics, Spectroscopy
Abstract: Physical review letters 109, 245003 (2012). doi:10.1103/PhysRevLett.109.245003, Published by APS, College Park, Md.
Published: 2016
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20. Soft X-ray scattering using FEL radiation for probing near-solid density plasmas at few electron volt temperatures

Author: Andreas Przystawik, R. Thiele, Ingo Uschmann, J. Mithen, E. Förster, Ronald Redmer, N. X. Truong, Josef Tiggesbäumker, Tilo Döppner, Franz Tavella, Gianluca Gregori, Karl-Heinz Meiwes-Broer, R. Irsig, R. R. Fäustlin, Siegfried Glenzer, Bin Li, Sebastian Göde, Tim Laarmann, L. Cao, Ulf Zastrau, S. Düsterer, Sven Toleikis, P. Radcliffe, Carsten Fortmann, Hyesog Lee, and Th. Tschentscher
Subjects: Physics, Nuclear and High Energy Physics, Radiation, Photon, Scattering, Astrophysics::High Energy Astrophysical Phenomena, Free-electron laser, DESY, Plasma, Inelastic scattering, Photon energy, Laser, law.invention, law, ddc:530, Atomic physics
Abstract: We report on soft X-ray scattering experiments on cryogenic hydrogen and simple metal samples. As a source of intense, ultrashort soft X-ray pulses we have used free-electron laser radiation at 92 eV photon energy from FLASH at DESY, Hamburg. X-ray pulses with energies up to 150 μJ and durations 15-50 fs provide interaction with the sample leading simultaneously to plasma formation and scattering. Experiments exploiting both of these interactions have been carried out, using the same experimental setup. Firstly, recording of soft X-ray inelastic scattering from near-solid density hydrogen plasmas at few electron volt temperatures confirms the feasibility of this diagnostics technique. Secondly, the soft X-ray excitation of few electron volt solid-density plasmas in bulk metal samples could be studied by recording soft X-ray line and continuum emission integrated over emission times from fs to ns. © 2009 Elsevier B.V.
Published: 2016
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21. Perspective for high energy density studies on X-ray FELs

Author: Sebastian Göde, R. Sobierajski, Gianluca Gregori, Michaela Kozlova, Gerd Röpke, Karel Saksl, Art J. Nelson, Jacek Krzywinski, Andreas Przystawik, K. S. Budil, S. Düsterer, Thomas Tschentscher, Justin Wark, Philip Heimann, Sven Toleikis, J. Cihelka, Thomas Dzelzainis, William E. White, Libor Juha, R. C. Cauble, Josef Tiggesbäumker, R. R. Fäustlin, Saša Bajt, T. Whitcher, R. Thiele, Fida Khattak, Bob Nagler, Heidi Reinholz, Richard W. Lee, Henry N. Chapman, Dorota Klinger, E. Förster, T. Bornath, Siegfried Glenzer, Carsten Fortmann, Tomáš Burian, Karl-Heinz Meiwes-Broer, Marta Fajardo, P. Mercere, Roger Falcone, Ronald Redmer, Tim Laarmann, Sam Vinko, Hyesog Lee, Věra Hájková, Ronnie Shepherd, Jerome B. Hastings, Ulf Zastrau, Marek Jurek, J. Chalupsky, William J. Murphy, Tilo Döppner, A.R. Khorsand, Ingo Uschmann, and David Riley
Subjects: Physics, Photon, business.industry, Parabolic reflector, Free-electron laser, DESY, Warm dense matter, Photodiode, law.invention, Optics, law, Physics::Accelerator Physics, Absorption (electromagnetic radiation), Spectroscopy, business
Abstract: We report on the x-ray absorption of Warm Dense Matter experiment at the FLASH Free Electron Laser (FEL) facility at DESY. The FEL beam is used to produce Warm Dense Matter with soft x-ray absorption as the probe of electronic structure. A multilayer-coated parabolic mirror focuses the FEL radiation, to spot sizes as small as 0.3μm in a ∼15fs pulse of containing >10 12 photons at 13.5 nm wavelength, onto a thin sample. Silicon photodiodes measure the transmitted and reflected beams, while spectroscopy provides detailed measurement of the temperature of the sample. The goal is to measure over a range of intensities approaching 10 18 W/cm 2. Experimental results will be presented along with theoretical calculations. A brief report on future FEL efforts will be given. © 2009 SPIE.
Published: 2016
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22. Warm dense aluminum plasma generated by the free-electron-laser FLASH

Author: Art J. Nelson, Ulf Zastrau, E. Förster, S. Toleikis, Eric Galtier, David Riley, Siegfried Glenzer, T. Tschentscher, Justin Wark, Thomas Dzelzainis, Frank B. Rosmej, Richard W. Lee, Bob Nagler, and Sam Vinko
Subjects: Physics, law, Physics::Atomic and Molecular Clusters, Bremsstrahlung, Free-electron laser, Saturable absorption, Photon energy, Warm dense matter, Atomic physics, Laser, Absorption (electromagnetic radiation), Spectroscopy, law.invention
Abstract: We report on experiments aimed at the generation and characterization of solid density plasmas at the free-electron laser FLASH in Hamburg. Aluminum samples were irradiated with XUV pulses at 13.5 nm wavelength (92 eV photon energy). The pulses with duration of a few tens of femtoseconds and pulse energy up to 100 μJ are focused to intensities ranging from 10 13 to 10 17 W/cm 2. We investigate the absorption and temporal evolution of the sample under irradiation by use of XUV spectroscopy. We discuss the origin of saturable absorption, radiative decay, bremsstrahlung and ionic line emission. Our experimental results are in good agreement with hydrodynamic simulations. © 2012 American Institute of Physics.
Published: 2016

23. Nanometer resolution optical coherence tomography using broad bandwidth XUV and soft x-ray radiation

Author: Alexander Blinne, Jens Viefhaus, E. Frumker, Christian Rödel, Vinzenz Hilbert, Martin Wünsche, Gerhard G. Paulus, Eckhart Förster, Silvio Fuchs, Paul B. Corkum, Ulf Zastrau, and Leif Glaser
Subjects: Water window, Multidisciplinary, Tomographic reconstruction, Materials science, medicine.diagnostic_test, business.industry, Infrared, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Article, 010309 optics, Optics, Optical coherence tomography, Extreme ultraviolet, 0103 physical sciences, Microscopy, medicine, ddc:000, Tomography, 0210 nano-technology, business, Coherence (physics)
Abstract: Optical coherence tomography (OCT) is a non-invasive technique for cross-sectional imaging. It is particularly advantageous for applications where conventional microscopy is not able to image deeper layers of samples in a reasonable time, e.g. in fast moving, deeper lying structures. However, at infrared and optical wavelengths, which are commonly used, the axial resolution of OCT is limited to about 1 μm, even if the bandwidth of the light covers a wide spectral range. Here, we present extreme ultraviolet coherence tomography (XCT) and thus introduce a new technique for non-invasive cross-sectional imaging of nanometer structures. XCT exploits the nanometerscale coherence lengths corresponding to the spectral transmission windows of, e.g., silicon samples. The axial resolution of coherence tomography is thus improved from micrometers to a few nanometers. Tomographic imaging with an axial resolution better than 18 nm is demonstrated for layer-type nanostructures buried in a silicon substrate. Using wavelengths in the water transmission window, nanometer-scale layers of platinum are retrieved with a resolution better than 8 nm. XCT as a nondestructive method for sub-surface tomographic imaging holds promise for several applications in semiconductor metrology and imaging in the water window.
Published: 2016
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24. Imaging Shock Waves in Diamond with Both High Temporal and Spatial Resolution at an XFEL

Author: Frank Seiboth, Martha A. Beckwith, Ulf Zastrau, Eric Galtier, Christian G. Schroer, Brice Arnold, Bob Nagler, Andrew Higginbotham, A. Schropp, Vivienne Meier, Gilbert Collins, Robert Hoppe, Hae Ja Lee, Jerome B. Hastings, Jens Patommel, Justin Wark, Yuan Ping, and Damien Hicks
Subjects: Physics, Shock wave, Multidisciplinary, business.industry, Astrophysics::High Energy Astrophysical Phenomena, Nonlinear optics, Diamond, engineering.material, Laser, Article, law.invention, Pulse (physics), Shock (mechanics), Optical pumping, Optics, law, ddc:000, State of matter, engineering, business
Abstract: The advent of hard x-ray free-electron lasers (XFELs) has opened up a variety of scientific opportunities in areas as diverse as atomic physics, plasma physics, nonlinear optics in the x-ray range and protein crystallography. In this article, we access a new field of science by measuring quantitatively the local bulk properties and dynamics of matter under extreme conditions, in this case by using the short XFEL pulse to image an elastic compression wave in diamond. The elastic wave was initiated by an intense optical laser pulse and was imaged at different delay times after the optical pump pulse using magnified x-ray phase-contrast imaging. The temporal evolution of the shock wave can be monitored, yielding detailed information on shock dynamics, such as the shock velocity, the shock front width and the local compression of the material. The method provides a quantitative perspective on the state of matter in extreme conditions.
Published: 2015
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25. Shot-to-shot intensity and wavefront stability of high-harmonic generation

Author: S. Künzel, Marta Fajardo, Guillaume Dovillaire, Philippe Zeitoun, Hamed Merdji, Bob Nagler, Ulf Zastrau, Willem Boutu, B. Barbrel, Hae Ja Lee, Eric Galtier, Gareth O. Williams, Richard W. Lee, Instituto de Telecomunicações [Lisboa, Portugal], Service des Photons, Atomes et Molécules (SPAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), SLAC National Accelerator Laboratory (SLAC), Stanford University, Lawrence Berkeley National Laboratory [Berkeley] (LBNL), Friedrich-Schiller-Universität = Friedrich Schiller University Jena [Jena, Germany], Imagine Optic, AFOP, Department of Psychics, Laboratoire d'optique appliquée (LOA), and École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Wavefront, Physics, Spectrometer, [PHYS.PHYS]Physics [physics]/Physics [physics], business.industry, Phase (waves), Wavefront sensor, Atomic and Molecular Physics, and Optics, Intensity (physics), Optics, Temporal resolution, High harmonic generation, Plasma diagnostics, Electrical and Electronic Engineering, business, Engineering (miscellaneous)
Abstract: International audience; We report on the shot-to-shot stability of intensity and spatial phase of high-harmonic generation (HHG). The intensity stability is measured for each high-harmonic (HH) order with a spectrometer. Additionally, the spatial phase is measured with an XUV wavefront sensor for a single HH order measured in a single shot, which according to our knowledge was not reported before with a Hartmann wavefront sensor. Furthermore, we compare the single-shot measurement of the spatial phase with time-integrated measurements and we show that the XUV wavefront sensor is a useful tool to simultaneously optimize the spatial phase and intensity of HHG within the available HHG parameter range used in this study.
Published: 2015
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26. X-ray absorption spectroscopy of iron at multimegabar pressures in laser shock experiments

Author: C. Fourment, Norimasa Ozaki, Jérôme Gaudin, Marion Harmand, Bob Nagler, Ryosuke Kodama, Motoaki Nakatsutsumi, Fabien Dorchies, Guillaume Morard, A. Denoeud, Yiping Feng, J. Bouchet, Stephane Mazevet, Kohei Miyanishi, Diling Zhu, R. Musella, Sven Toleikis, Tommaso Vinci, M. Koenig, Alessandra Benuzzi-Mounaix, Alessandra Ravasio, François Guyot, Ulf Zastrau, H. J. Lee, V. Recoules, Eric Galtier, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), Laboratoire pour l'utilisation des lasers intenses (LULI), Université Pierre et Marie Curie - Paris 6 (UPMC)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), DAM Île-de-France (DAM/DIF), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Centre d'Etudes Lasers Intenses et Applications (CELIA), Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Bordeaux (UB), SLAC National Accelerator Laboratory (SLAC), Stanford University, Institute of Laser Engineering, Osaka University, Osaka, Japan, affiliation inconnue, European XFEL GmbH (XFEL), European XFEL GmbH, Photone Sciences, Deutsches Elektronen-Synchrotron (DESY), Friedrich-Schiller-Universität = Friedrich Schiller University Jena [Jena, Germany], ANR-12-PDOC-0011,IronFEL,Le fer et ses alliages sous conditions extrèmes et sondés par diagnostiques X sur les installations FEL et lasers intenses(2012), ANR-12-BS04-0015,PlanetLab,Propriètés des planètes et des exoplanètes en laboratoire(2012), Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC), Université Paris-Saclay-Université Pierre et Marie Curie - Paris 6 (UPMC)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), SLAC National Accelerator Laboratory, Friedrich-Schiller-Universität Jena, Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), and Université de Bordeaux (UB)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: X-ray absorption spectroscopy, Materials science, Free-electron laser, Diamond, [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph], engineering.material, Condensed Matter Physics, Laser, 01 natural sciences, Molecular physics, XANES, Spectral line, 010305 fluids & plasmas, Electronic, Optical and Magnetic Materials, law.invention, law, [PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph], 0103 physical sciences, engineering, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], ddc:530, 010306 general physics, Spectroscopy, Absorption (electromagnetic radiation)
Abstract: International audience; Taking advantage of the new opportunities provided by x-ray free electron laser (FEL) sources when coupled to a long laser pulse as available at the Linear Coherent Light Source (LCLS), we have performed x-ray absorption near-edge spectroscopy (XANES) of laser shock compressed iron up to 420 GPa (±50) and 10 800 K (±1390). Visible diagnostics coupled with hydrodynamic simulations were used to infer the thermodynamical conditions along the Hugoniot and the release adiabat. A modification of the pre-edge feature at 7.12 keV in the XANES spectra is observed above pressures of 260 GPa along the Hugoniot. Comparing with ab initio calculations and with previous laser-heated diamond cell data, we propose that such changes in the XANES pre-edge could be a signature of molten iron. This interpretation then suggests that iron is molten at pressures and temperatures higher than 260 GPa (±29) and 5680 K (±700) along the principal Fe Hugoniot.
Published: 2015
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27. The Matter in Extreme Conditions instrument at the Linac Coherent Light Source

Author: Justin Garofoli, G. Hays, Lori Plummer, Alex Wallace, Richard W. Lee, A. Schropp, Zhou Xing, Eduardo Granados, Gary Bouchard, Jing Yin, James Young, J. B. Hastings, Richard M. Boyce, Brice Arnold, Marc Campell, Ruben Curiel, Alice Callen, Hae Ja Lee, Marc Welch, Bob Nagler, Despina Milathianaki, Ulf Zastrau, Eric Galtier, Philip Heimann, William E. White, and Richard F. Boyce
Subjects: Nuclear and High Energy Physics, Astrophysics::High Energy Astrophysical Phenomena, Nanotechnology, Linear particle accelerator, law.invention, high-pressure science, Optics, law, Instrumentation (computer programming), Free-Electron Lasers, Instrumentation, Laser beams, FEL, Physics, Radiation, business.industry, Particle accelerator, Warm dense matter, high energy density science, warm dense matter, X-ray Thomson scattering, Beamline, ddc:540, Transient (oscillation), business, Beam (structure)
Abstract: A description of the Matter in Extreme Conditions instrument at the Linac Coherent Light Source is given. Recent scientific highlights illustrate phase-contrast imaging of shock waves, X-ray Thomson scattering and X-ray diffraction of shocked materials., The LCLS beam provides revolutionary capabilities for studying the transient behavior of matter in extreme conditions. The particular strength of the Matter in Extreme Conditions instrument is that it combines the unique LCLS beam with high-power optical laser beams, and a suite of dedicated diagnostics tailored for this field of science. In this paper an overview of the beamline, the capabilities of the instrumentation, and selected highlights of experiments and commissioning results are presented.
Published: 2015
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28. Equilibration dynamics and conductivity of warm dense hydrogen

Author: Bastian Holst, R. Bredow, H. J. Lee, Michael Schulz, Rolf Mitzner, Tim Laarmann, Thomas Tschentscher, Thomas Fennel, S. Dziarzhytski, Ulf Zastrau, Michael Wöstmann, S. Roling, Sebastian Göde, Eckhart Förster, Carsten Fortmann, S. H. Glenzer, Gianluca Gregori, Helmut Zacharias, Thomas G. White, T. Bornath, Sven Toleikis, Marion Harmand, Josef Tiggesbäumker, B. Siemer, Luke Fletcher, Andreas Przystawik, Paul Neumayer, P. Sperling, Ronald Redmer, S. Skruszewicz, Tilo Döppner, C. D. Murphy, Motoaki Nakatsutsumi, Tammy Ma, Hilbert, J. Mithen, and Andreas Becker
Subjects: Materials science, Hydrogen, Plasma parameters, chemistry.chemical_element, Electrons, Electron, Molecular Dynamics Simulation, Photon energy, 7. Clean energy, 01 natural sciences, 010305 fluids & plasmas, Ion, X-Ray Diffraction, Ionization, 0103 physical sciences, ddc:530, 010306 general physics, Lasers, Electric Conductivity, Temperature, DESY, Plasma, chemistry, Hydrodynamics, Quantum Theory, Atomic physics
Abstract: We investigate subpicosecond dynamics of warm dense hydrogen at the XUV free-electron laser facility (FLASH) at DESY (Hamburg). Ultrafast impulsive electron heating is initiated by a â‰300-fs short x-ray burst of 92-eV photon energy. A second pulse probes the sample via x-ray scattering at jitter-free variable time delay. We show that the initial molecular structure dissociates within (0.9±0.2) ps, allowing us to infer the energy transfer rate between electrons and ions. We evaluate Saha and Thomas-Fermi ionization models in radiation hydrodynamics simulations, predicting plasma parameters that are subsequently used to calculate the static structure factor. A conductivity model for partially ionized plasma is validated by two-temperature density-functional theory coupled to molecular dynamic simulations and agrees with the experimental data. Our results provide important insights and the needed experimental data on transport properties of dense plasmas. © 2014 American Physical Society.
Published: 2014
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29. Resolving ultrafast heating of dense cryogenic hydrogen

Author: J. Tiggesbäumker, J. Mithen, Motoaki Nakatsutsumi, V. Hilbert, Tammy Ma, Michael Schulz, Rolf Mitzner, R. Bredow, Thomas G. White, Helmut Zacharias, Gianluca Gregori, Eckhart Förster, Luke Fletcher, D Hochhaus, Sebastian Göde, Th. Tschentscher, Bastian Holst, S. Dziarzhytski, P. Sperling, C. D. Murphy, Sven Toleikis, Paul Neumayer, Andreas Becker, Tilo Döppner, Michael Wöstmann, S. H. Glenzer, S. Roling, S. Skruszewicz, B. Siemer, Andreas Przystawik, Ronald Redmer, Marion Harmand, T. Bornath, H. J. Lee, Tim Laarmann, Thomas Fennel, and Ulf Zastrau
Subjects: Physics, Hydrogen, Free-electron laser, General Physics and Astronomy, chemistry.chemical_element, Plasma, Conductivity, 7. Clean energy, Scattering amplitude, chemistry, Rise time, Ionization, ddc:550, Atomic physics, Ultrashort pulse
Abstract: We report on the dynamics of ultrafast heating in cryogenic hydrogen initiated by a ≲300 fs, 92 eV free electron laser x-ray burst. The rise of the x-ray scattering amplitude from a second x-ray pulse probes the transition from dense cryogenic molecular hydrogen to a nearly uncorrelated plasmalike structure, indicating an electron-ion equilibration time of ∼0.9 ps. The rise time agrees with radiation hydrodynamics simulations based on a conductivity model for partially ionized plasma that is validated by two-temperature density-functional theory. © 2014 American Physical Society.
Published: 2014
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30. Bent crystal spectrometer for both frequency and wavenumber resolved x-ray scattering at a seeded free-electron laser

Author: Philipp Heimann, Eckhart Foerster, Heike Marschner, Ulf Zastrau, Eric Galtier, Luke Fletcher, Siegfried Glenzer, O. Wehrhan, Andreas Schropp, Eliseo Gamboa, Bob Nagler, and Hae Ja Lee
Subjects: Physics, Spectrometer, Scattering, Free-electron laser, FOS: Physical sciences, Laser, Spectral line, Physics - Plasma Physics, law.invention, Plasma Physics (physics.plasm-ph), Amplitude, law, Wavenumber, ddc:530, Atomic physics, Instrumentation, Plasmon
Abstract: We present a cylindrically curved GaAs x-ray spectrometer with energy resolution $\Delta E/E = 1.1\cdot 10^{-4}$ and wave-number resolution of $\Delta k/k = 3\cdot 10^{-3}$, allowing plasmon scattering at the resolution limits of the Linac Coherent Light Source (LCLS) x-ray free-electron laser. It spans scattering wavenumbers of 3.6 to $5.2/$\AA\ in 100 separate bins, with only 0.34\% wavenumber blurring. The dispersion of 0.418~eV/$13.5\,\mu$m agrees with predictions within 1.3\%. The reflection homogeneity over the entire wavenumber range was measured and used to normalize the amplitude of scattering spectra. The proposed spectrometer is superior to a mosaic HAPG spectrometer when the energy resolution needs to be comparable to the LCLS seeded bandwidth of 1~eV and a significant range of wavenumbers must be covered in one exposure.
Published: 2014
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31. Focusing XFEL SASE Pulses by Rotationally Parabolic Refractive X-Ray Lenses

Author: A. Schropp, Jerome B. Hastings, Robert Hoppe, Fredrik Uhlén, Brice Arnold, Frank Seiboth, Daniel Nilsson, Ulf Zastrau, Bob Nagler, Jens Patommel, Vivienne Meier, Christian G. Schroer, Ulrich Vogt, Hans M. Hertz, Eric Galtier, and Hae Ja Lee
Subjects: Physics, History, Range (particle radiation), business.industry, X-ray, Physics::Optics, chemistry.chemical_element, Laser, Electromagnetic radiation, Linear particle accelerator, Spectral line, Computer Science Applications, Education, law.invention, Optics, chemistry, law, Chromatic aberration, Physics::Accelerator Physics, Optoelectronics, ddc:530, Beryllium, business
Abstract: Using rotationally parabolic refractive x-ray lenses made of beryllium, we focushard x-ray free-electron laser pulses of the Linac Coherent Light Source (LCLS) down to aspot size in the 100 nm range. We demonstrated efficient nanofocusing and characterizedthe nanofocused wave field by ptychographic imaging [A. Schropp, et al., Sci. Rep. 3, 1633(2013)] in the case of monochromatic LCLS pulses produced by a crystal monochromator thatdecreases the LCLS bandwidth down to ∆E/E = 1.4 · 10 −4 . The full spectrum of LCLSpulses generated by self-amplified spontaneous emission (SASE), however, fluctuates and hasa typical bandwidth of a few per mille (∆E/E ≈ 2 · 10 −3 ). Due to the dispersion in the lensmaterial, a polychromatic nanobeam generated by refractive x-ray lenses is affected by chromaticaberration. After reviewing the chromaticity of refractive x-ray lenses, we discuss the influenceof increased bandwidth on the quality of a nanofocused SASE pulse.
Published: 2014
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32. Full spatial characterization of a nanofocused x-ray free-electron laser beam by ptychographic imaging

Author: Eric Galtier, A. Schropp, Frank Seiboth, Hae Ja Lee, Daniel Nilsson, Vivienne Meier, Brice Arnold, Ulf Zastrau, Hans M. Hertz, Jerome B. Hastings, Jens Patommel, Ulrich Vogt, Fredrik Uhlén, Bob Nagler, Christian G. Schroer, and Robert Hoppe
Subjects: Free electron model, Physics, Multidisciplinary, Field (physics), business.industry, Free-electron laser, Bioinformatics, Laser, Article, Characterization (materials science), Intensity (physics), law.invention, Optics, law, Caustic (optics), business, Beam (structure)
Abstract: The emergence of hard X-ray free electron lasers (XFELs) enables new insights into many fields of science. These new sources provide short, highly intense, and coherent X-ray pulses. In a variety of scientific applications these pulses need to be strongly focused. In this article, we demonstrate focusing of hard X-ray FEL pulses to 125 nm using refractive x-ray optics. For a quantitative analysis of most experiments, the wave field or at least the intensity distribution illuminating the sample is needed. We report on the full characterization of a nanofocused XFEL beam by ptychographic imaging, giving access to the complex wave field in the nanofocus. From these data, we obtain the full caustic of the beam, identify the aberrations of the optic, and determine the wave field for individual pulses. This information is for example crucial for high-resolution imaging, creating matter in extreme conditions, and nonlinear x-ray optics.
Published: 2013

33. An extreme ultraviolet Michelson interferometer for experiments at free-electron lasers

Author: T. Kämpfer, Alexander Blinne, Torsten Feigl, Martin Wünsche, Christian Rödel, Ulf Zastrau, Vinzenz Hilbert, Gerhard G. Paulus, Ingo Uschmann, Eckhart Förster, Silvio Fuchs, and Publica
Subjects: Physics, Interferometric visibility, business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, Michelson interferometer, Laser, law.invention, Interferometry, Optics, law, Extreme ultraviolet, Astronomical interferometer, Optoelectronics, ddc:530, business, Instrumentation, Twyman–Green interferometer, Coherence (physics)
Abstract: Review of scientific instruments 84(9), 095111-1 -095111-6 (2013). doi:10.1063/1.4821146, We present a Michelson interferometer for 13.5 nm soft x-ray radiation. It is characterized in a proof of-principle experiment using synchrotron radiation, where the temporal coherence is measured to be 13 fs. The curvature of the thin-film beam splitter membrane is derived from the observed fringe pattern. The applicability of this Michelson interferometer at intense free-electron lasers is investigated,particularly with respect to radiation damage. This study highlights the potential role of such Michelson interferometers in solid density plasma investigations using, for instance, extreme soft x-ray free electron lasers. A setup using the Michelson interferometer for pseudo-Nomarski-interferometry is proposed., Published by American Institute of Physics
Published: 2013
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34. Direct Measurements of the Ionization Potential Depression in a Dense Plasma

Author: Jaromír Chalupský, Jacek Krzywinski, C. R. D. Brown, Roger Falcone, Catherine Graves, Libor Juha, P.A. Heimann, Byoung-ick Cho, Yuan Ping, Diling Zhu, C. D. Murphy, L. Vysin, Věra Hájková, Ulf Zastrau, William F. Schlotter, O. Ciricosta, R. W. Lee, Joshua J. Turner, Benny Wu, Marc Messerschmidt, Tianhan Wang, Hyun-Kyung Chung, Hae Ja Lee, D. S. Rackstraw, Tomáš Burian, K. Engelhorn, Andreas Scherz, Bob Nagler, Justin Wark, Sven Toleikis, Sam Vinko, and Andrew Higginbotham
Subjects: Physics, General Physics and Astronomy, Plasma, Photon energy, 01 natural sciences, Fluorescence, Measure (mathematics), Linear particle accelerator, 010305 fluids & plasmas, Ion, Position (vector), 0103 physical sciences, ddc:550, Ionization energy, Atomic physics, 010306 general physics
Abstract: We have used the Linac Coherent Light Source to generate solid-density aluminum plasmas at temperatures of up to 180 eV. By varying the photon energy of the x rays that both create and probe the plasma, and observing the $K\mathrm{\text{\ensuremath{-}}}\ensuremath{\alpha}$ fluorescence, we can directly measure the position of the $K$ edge of the highly charged ions within the system. The results are found to disagree with the predictions of the extensively used Stewart-Pyatt model, but are consistent with the earlier model of Ecker and Kr\"oll, which predicts significantly greater depression of the ionization potential.
Published: 2012
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35. Probing near-solid density plasmas using soft x-ray scattering

Author: Sebastian Göde, Gianluca Gregori, Siegfried Glenzer, Th. Tschentscher, Bin Li, Carsten Fortmann, S Toleikis, Karl-Heinz Meiwes-Broer, Tilo Döppner, Th. Bornath, P. Radcliffe, R. Thiele, T. Whitcher, Andreas Przystawik, Tim Laarmann, R. Irsig, Gerd Röpke, Ulf Zastrau, Ronald Redmer, H. Reinholz, F. Tavella, Stefan Düsterer, Sam Vinko, Bob Nagler, Harald Redlin, J. Tiggesbäumker, R. R. Fäustlin, Hae Ja Lee, Ingo Uschmann, J. Mithen, Eckhart Förster, Beata Ziaja, Deutsches Elektronen-Synchrotron [Hamburg] (DESY), Institut für Physik, Universität Rostock, Lawrence Livermore National Laboratory (LLNL), Institut für Optik und Quantenelektronik, Friedrich-Schiller-Universität = Friedrich Schiller University Jena [Jena, Germany], Department of Physics and Astronomy [UCLA, Los Angeles], University of California [Los Angeles] (UCLA), University of California-University of California, Clarendon Laboratory [Oxford], University of Oxford [Oxford], SLAC National Accelerator Laboratory (SLAC), Stanford University, Central Laser Facility (CLF), STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC)-Science and Technology Facilities Council (STFC), European XFEL GmbH, and Institute of Nuclear Physics
Subjects: Physics, Scattering, Laser pumping, Plasma, Warm dense matter, Condensed Matter Physics, Laser, 01 natural sciences, Atomic and Molecular Physics, and Optics, 010305 fluids & plasmas, law.invention, Optical pumping, and scattering of electromagnetic radiation 52.50.Jm, law, 0103 physical sciences, State of matter, 41.60.Cr Free-electron lasers 52.20.Fs Electron collisions 52.25.Os Emission, Atomic physics, 010306 general physics, absorption, Ultrashort pulse
Abstract: International audience; X-ray scattering using highly brilliant X-ray free-electron laser (FEL) radiation provides a new access to probe free electron density, temperature and ionization in near-solid density plasmas. First experiments at the soft X-ray FEL FLASH at DESY, Hamburg, show the capabilities of this technique. The ultrashort FEL pulses in particular can probe equilibration phenomena occurring after excitation of the plasma using ultrashort optical laser pumping. We have investigated liquid hydrogen and find that the interaction of very intense soft X-ray FEL radiation alone heats the sample volume. As the plasma establishes, photons from the same pulse undergo scattering, thus probing the transient, warm dense matter state. We find a free electron density of (2.6 ± 0.2) · 10 20 cm −3 and an electron temperature of 14 ± 3.5 eV. In pump-probe experiments, using intense optical laser pulses to generate more extreme states of matter, this interaction of the probe pulse has to be considered in the interpretation of scattering data. In this paper we present details of the experimental setup at FLASH and the diagnostic methods used to quantitatively analyze the data. Probing near-solid density plasmas using soft X-ray scattering 2 Plasma production and heating by laser beams Probing near-solid density plasmas using soft X-ray scattering 3
Published: 2010
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36. Observation of ultrafast nonequilibrium collective dynamics in warm dense hydrogen

Author: R. Irsig, H. J. Lee, R. Thiele, Siegfried Glenzer, Carsten Fortmann, J. Mithen, S. Düsterer, Heidi Reinholz, Karl-Heinz Meiwes-Broer, T. Whitcher, B. Li, Gianluca Gregori, Tilo Döppner, Bob Nagler, Harald Redlin, Sam Vinko, J. Tiggesbäumker, Andreas Przystawik, T. Bornath, Eckhart Förster, R. R. Fäustlin, Beata Ziaja, Gerd Röpke, Sebastian Göde, Franz Tavella, Sven Toleikis, Tim Laarmann, Ulf Zastrau, Ronald Redmer, Ingo Uschmann, and Th. Tschentscher
Subjects: Physics, Electron density, Hydrogen, Thomson scattering, General Physics and Astronomy, chemistry.chemical_element, Electron, Plasma, Inelastic scattering, 7. Clean energy, 01 natural sciences, 010305 fluids & plasmas, chemistry, Physics::Plasma Physics, Ionization, 0103 physical sciences, ddc:550, Electron temperature, Atomic physics, 010306 general physics
Abstract: We investigate ultrafast (fs) electron dynamics in a liquid hydrogen sample, isochorically and volumetrically heated to a moderately coupled plasma state. Thomson scattering measurements using 91.8 eV photons from the free-electron laser in Hamburg (FLASH at DESY) show that the hydrogen plasma has been driven to a nonthermal state with an electron temperature of 13 eV and an ion temperature below 0.1 eV, while the free-electron density is 2.8x10{20} cm{-3}. For dense plasmas, our experimental data strongly support a nonequilibrium kinetics model that uses impact ionization cross sections based on classical free-electron collisions.
Published: 2010
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37. A compact soft X-ray spectrograph combining high efficiency and resolution

Author: Ingo Uschmann, R. R. Fäustlin, Sven Toleikis, E. Förster, Th. Tschentscher, and Ulf Zastrau
Subjects: Physics, Thomson scattering, business.industry, Bremsstrahlung, Solid angle, Grating, Optics, Shutter, Pinhole (optics), Plasma diagnostics, ddc:610, business, Instrumentation, Spectrograph, Mathematical Physics
Abstract: A compact and light weight soft X-ray spectrograph covering 5−35 nm and employing a toroidal mirror and a variable line space reflection grating has been newly developed. Particular emphasis has been placed on achieving a large collection solid angle (1.9 × 10−3 sr) and a high efficiency of the components in order to enable Thomson Scattering plasma diagnostics which has a small total cross section (6.65 × 10−25 cm2). The instrument achieves a signal-to-noise ratio of 5 with a 13.5 nm source which isotropically emits 2.5 × 105 photons. A resolution λ/Δλ = 330 was measured at 21 nm and the dispersion was calibrated. The instrument is housed inside a DN 100 CF ultra high vacuum manipulator (43 × 46 × 47 cm3) which allows positioning relative to the source within ±5 mm and ±50 mm in X,Y and Z direction, respectively. It can be used with or without entrance pinhole and is equipped with a motorized grating, a filter wheel with five filters, and a shutter. Altogether, these features make the spectrograph a versatile instrument which can be employed in a variety of physics applications such as line and bremsstrahlung spectroscopy or Thomson scattering.
Published: 2010
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38. Electronic Structure of an XUV Photogenerated Solid-Density Aluminum Plasma

Author: J. Tiggesbäumker, Gianluca Gregori, Tilo Döppner, Eric Galtier, Justin Wark, Libor Juha, Sven Toleikis, Thomas Dzelzainis, Karl-Heinz Meiwes-Broer, E. Förster, S. Düsterer, P.A. Heimann, Thomas Tschentscher, Ryszard Sobierajski, Bob Nagler, Stephane Mazevet, T. Whitcher, Henry N. Chapman, R. Thiele, R W Lee, Andreas Przystawik, Frank B. Rosmej, Tim Laarmann, Tomáš Burian, Carsten Fortmann, Franz Tavella, L. Vysin, R. R. Fäustlin, Domenico Doria, Ulf Zastrau, Marek Jurek, Siegfried Glenzer, Jaromir Chalupsky, David Riley, Steven R. White, Ronald Redmer, B. Li, Sam Vinko, Janos Hajdu, Sebastian Göde, Art J. Nelson, H. J. Lee, J. Mithen, Jakob Andreasson, R. Irsig, J. Cihelka, Jacek Krzywinski, Saša Bajt, Věra Hájková, and XUV Optics
Subjects: Physics, METIS-316788, Plasma Gases, Ultraviolet Rays, General Physics and Astronomy, Electrons, Electronic structure, Electron, Plasma, Photochemical Processes, Laser, 01 natural sciences, 010305 fluids & plasmas, law.invention, law, Excited state, 0103 physical sciences, State of matter, Physics::Atomic and Molecular Clusters, ddc:550, Density functional theory, Emission spectrum, Atomic physics, 010306 general physics, Aluminum
Abstract: By use of high intensity XUV radiation from the FLASH free-electron laser at DESY, we have created highly excited exotic states of matter in solid-density aluminum samples. The XUV intensity is sufficiently high to excite an inner-shell electron from a large fraction of the atoms in the focal region. We show that soft-x-ray emission spectroscopy measurements reveal the electronic temperature and density of this highly excited system immediately after the excitation pulse, with detailed calculations of the electronic structure, based on finite-temperature density functional theory, in good agreement with the experimental results.
Published: 2010
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39. Soft X-Ray Thomson scattering in warm dense hydrogen at FLASH

Author: E. Förster, Karl-Heinz Meiwes-Broer, Th. Bornath, Franz Tavella, Josef Tiggesbäumker, Gerd Röpke, R. Thiele, Ingo Uschmann, Andreas Przystawik, Ronald Redmer, Tilo Döppner, R. R. Fäustlin, Gianluca Gregori, R. Irsig, Sven Toleikis, Tim Laarmann, Ulf Zastrau, Sebastian Göde, Siegfried Glenzer, J. Mithen, S. Düsterer, Carsten Fortmann, Harald Redlin, Heidi Reinholz, Bowei Li, Hyesog Lee, and Th. Tschentscher
Subjects: Free electron model, Physics, law, Thomson scattering, Scattering, Physics::Plasma Physics, Free-electron laser, Electron, Plasma, Atomic physics, Warm dense matter, Laser, law.invention
Abstract: We present collective Thomson scattering with soft x-ray free electron laser radiation as a method to track the evolution of warm dense matter plasmas with ∼200 fs time resolution. In a pump-probe scheme an 800 nm laser heats a 20 ∼m hydrogen droplet to the plasma state. After a variable time delay in the order of ps the plasma is probed by an x-ray ultra violet (XUV) pulse which scatters from the target and is recorded spectrally. Alternatively, in a self-Thomson scattering experiment, a single XUV pulse heats the target while a portion of its photons are being scattered probing the target. From such inelastic x-ray scattering spectra free electron temperature and density can be inferred giving insight on relaxation time scales in plasmas as well as the equation of state. We prove the feasibility of this method in the XUV range utilizing the free electron laser facility in Hamburg, FLASH. We recorded Thomson scattering spectra for hydrogen plasma, both in the self-scattering and in the pump-probe mode using optical laser heating. © 2009 SPIE-.
Published: 2009

40. Turning solid aluminium transparent by intense soft X-ray photoionization

Author: Dorota Klinger, P.A. Heimann, Ryszard Sobierajski, Gianluca Gregori, R. Thiele, R. Schott, Marta Fajardo, S. Duesterer, Karel Saksl, Libor Juha, Carsten Fortmann, Justin Wark, David Riley, Tilo Döppner, Karl-Heinz Meiwes-Broer, T. Whitcher, R. R. Fäustlin, Sven Toleikis, Jacek Krzywinski, J. Tiggesbäumker, Jaromir Chalupsky, P. Mercere, Saša Bajt, Tim Laarmann, Andreas Przystawik, Fida Khattak, Ulf Zastrau, J. Cihelka, Marek Jurek, Hyesog Lee, S. H. Glenzer, Bob Nagler, S. M. Vinko, Eckhart Förster, Sebastian Göde, Thomas Tschentscher, H.J. Vollmer, William J. Murphy, Thomas Dzelzainis, Heidi Reinholz, Richard W. Lee, Tomáš Burian, Elsa Abreu, Michaela Kozlova, Gerd Röpke, Eric Galtier, Art J. Nelson, Ronald Redmer, Ingo Uschmann, A.R. Khorsand, Frank B. Rosmej, Henry N. Chapman, T. Bornath, and Věra Hájková
Subjects: Physics, Optical physics, General Physics and Astronomy, chemistry.chemical_element, Saturable absorption, Photoionization, Plasma, Physicist, Warm dense matter, chemistry, Aluminium, Physics::Space Physics, ddc:530, Atomic physics, Inertial confinement fusion
Abstract: Saturable absorption is a phenomenon readily seen in the optical and infrared wavelengths. It has never been observed in core-electron transitions owing to the short lifetime of the excited states involved and the high intensities of the soft X-rays needed. We report saturable absorption of an L-shell transition in aluminium using record intensities over 10 16 W cm 2 at a photon energy of 92 eV. From a consideration of the relevant timescales, we infer that immediately after the X-rays have passed, the sample is in an exotic state where all of the aluminium atoms have an L-shell hole, and the valence band has approximately a 9 eV temperature, whereas the atoms are still on their crystallographic positions. Subsequently, Auger decay heats the material to the warm dense matter regime, at around 25 eV temperatures. The method is an ideal candidate to study homogeneous warm dense matter, highly relevant to planetary science, astrophysics and inertial confinement fusion. © 2009 Macmillan Publishers Limited. All rights reserved.
Published: 2009
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41. Bremsstrahlung and line spectroscopy of warm dense aluminum plasma heated by xuv free-electron-laser radiation

Author: Andreas Przystawik, S. Düsterer, H J Lee, Thomas Tschentscher, L. F. Cao, Heidi Reinholz, R. R. Fäustlin, Siegfried Glenzer, J. Tiggesbäumker, P. Radcliffe, I. Uschmann, Carsten Fortmann, Tim Laarmann, N. X. Truong, Ulf Zastrau, Gerd Röpke, August Wierling, Ronald Redmer, Sven Toleikis, Tilo Döppner, R. Thiele, Gianluca Gregori, and Eckhart Förster
Subjects: Physics, law, Extreme ultraviolet, Bremsstrahlung, ddc:530, Plasma, Electron, Atomic physics, Radiation, Spectroscopy, Laser, Intensity (heat transfer), law.invention
Abstract: We report the creation of solid-density aluminum plasma using free-electron laser (FEL) radiation at $13.5\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ wavelength. Ultrashort pulses were focused on a bulk Al target, yielding an intensity of $2\ifmmode\times\else\texttimes\fi{}{10}^{14}\phantom{\rule{0.3em}{0ex}}\mathrm{W}∕{\mathrm{cm}}^{2}$. The radiation emitted from the plasma was measured using an xuv spectrometer. Bremsstrahlung and line intensity ratios yield consistent electron temperatures of about $38\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$, supported by radiation hydrodynamics simulations. This shows that xuv FELs heat up plasmas volumetrically and homogeneously at warm-dense-matter conditions, which are accurately characterized by xuv spectroscopy.
Published: 2008
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42. Ablation of solids using a femtosecond extreme ultraviolet free electron laser

Author: S. Düsterer, Thomas Tschentscher, Dorota Klinger, D. von der Linde, E. Förster, Ulf Zastrau, Marek Jurek, Andriy Velyhan, Jaroslav Kuba, Libor Juha, Robert Nietubyć, J. Cihelka, Sven Toleikis, Harald Redlin, F. Perner, Klaus Sokolowski-Tinten, Nikola Stojanovic, Jerzy B. Pelka, Věra Hájková, S. Koptyaev, Jaromir Chalupsky, Jacek Krzywinski, and R. Sobierajski
Subjects: Laser ablation, Materials science, genetic structures, Physics and Astronomy (miscellaneous), business.industry, Free-electron laser, Physics::Optics, Radiation, eye diseases, Optics, Physics::Plasma Physics, Picosecond, Extreme ultraviolet, Femtosecond, Physics::Atomic and Molecular Clusters, Optoelectronics, ddc:530, sense organs, Penetration depth, business, Absorption (electromagnetic radiation)
Abstract: The ablation of solids by high energy femtosecond pulses from an extreme ultraviolet (XUV) free electron laser has been investigated using picosecond optical imaging. The time-resolved measurements are supplemented by an analysis of the permanent structural surface modifications. Compared with femtosecond optical excitation, distinct differences in the material response are found which are attributed to the increased penetration depth of the XUV radiation and the absence of any absorption nonlinearities.
Published: 2006
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43. Optical coherence tomography using broad-bandwidth XUV and soft X-ray radiation

Author: J. Bierbach, Ulf Zastrau, Christian Rödel, Alexander Blinne, Vinzenz Hilbert, Martin Wünsche, E. Förster, Silvio Fuchs, E. Frumker, and Gerhard G. Paulus
Subjects: Water window, Materials science, medicine.diagnostic_test, Spectrometer, Physics and Astronomy (miscellaneous), business.industry, General Engineering, General Physics and Astronomy, Physics and Astronomy(all), Synchrotron, law.invention, Optics, Optical coherence tomography, Physics::Plasma Physics, law, Extreme ultraviolet, medicine, business, Penetration depth, Image resolution, Coherence (physics)
Abstract: We present a novel approach to extend optical coherence tomography (OCT) to the extreme ultraviolet (XUV) and soft X-ray (SXR) spectral range. With a simple setup based on Fourier-domain OCT and adapted for the application of XUV and SXR broadband radiation, cross-sectional images of semiconductors and organic samples becomes feasible with current synchrotron or laser-plasma sources. For this purpose, broadband XUV radiation is focused onto the sample surface, and the reflected spectrum is recorded by an XUV spectrometer. The proposed method has the particular advantage that the axial spatial resolution only depends on the spectral bandwidth. As a consequence, the theoretical resolution limit of XUV coherence tomography (XCT) is in the order of nanometers, e.g., 3 nm for wavelengths in the water window (280–530 eV). We proved the concept of XCT by calculating the reflectivity of one-dimensional silicon and boron carbide samples containing buried layers and found the expected properties with respect to resolution and penetration depth confirmed.
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44. Tracking the ultrafast XUV optical properties of x-ray free-electron-laser heated matter with high-order harmonics

Author: P. Renaudin, S. Künzel, Bianca Iwan, A. I. Gonzalez, Eric Galtier, V. Recoules, Marta Fajardo, Hamed Merdji, Gareth O. Williams, C. Blancard, A. G. de la Varga, Hae Ja Lee, V. Hilbert, Richard W. Lee, Guillaume Dovillaire, P. Audebert, Willem Boutu, Eduardo Granados, P.A. Heimann, Pedro Velarde, Bob Nagler, B. Barbrel, James Dunn, Ulf Zastrau, S. Daboussi, Ph. Zeitoun, GoLP/Instituto de Plasmas e Fusão Nuclear-Laboratório Associado, Instituto Superior Técnico, Universidade Técnica de Lisboa (IST), Inst Super Tecn, GoLP Inst Plasmas & Fusao Nucl, Laboratoire d'optique appliquée (LOA), École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Institute of optics and quantum electronics, Friedrich-Schiller-Universität = Friedrich Schiller University Jena [Jena, Germany], Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Attophysique (ATTO), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), European XFEL GmbH (XFEL), European XFEL GmbH, Centre for Water Research (CWR), The University of Western Australia (UWA), SLAC National Accelerator Laboratory (SLAC), Stanford University, Lawrence Berkeley National Laboratory [Berkeley] (LBNL), Laboratoire pour l'utilisation des lasers intenses (LULI), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Imagine Optic, AFOP, Lawrence Livermore National Laboratory (LLNL), DAM Île-de-France (DAM/DIF), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Instituto de Fusión Nuclear, Universidad Politécnica de Madrid (UPM), GoLP/Instituto Superior Tecnico, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Free electron model, Free-electron laser, Electron, Warm dense matter, Laser, 01 natural sciences, 010305 fluids & plasmas, law.invention, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, [PHYS.MECA.MEMA]Physics [physics]/Mechanics [physics]/Mechanics of materials [physics.class-ph], law, 0103 physical sciences, Femtosecond, Atomic physics, 010306 general physics, Absorption (electromagnetic radiation), Ultrashort pulse
Abstract: International audience; We present measurements of photon absorption by free electrons as a solid is transformed to plasma. A femtosecond x-ray free-electron laser is used to heat a solid, which separates the electron and ion heating time scales. The changes in absorption are measured with an independent probe pulse created through high-order-harmonic generation. We find an increase in electron temperature to have a relatively small impact on absorption, contrary to several predictions, whereas ion heating increases absorption. We compare the data to current theoretical and numerical approaches and find that a smoother electronic structure yields a better fit to the data, suggestive of a temperature-dependent electronic structure in warm dense matter.
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45. Clocking Femtosecond Collisional Dynamics via Resonant X-Ray Spectroscopy

Author: Jacek Krzywinski, Sam Vinko, Věra Hájková, Libor Juha, Pedro Velarde, Jaromír Chalupský, Justin Wark, Michael P. Minitti, O. Ciricosta, V. Vozda, A. G. de la Varga, Richard W. Lee, Ulf Zastrau, Hyun-Kyung Chung, Georgi L. Dakovski, Elisa Fernandez-Tello, Tomáš Burian, P. Hollebon, Q. Y. van den Berg, and T. R. Preston
Subjects: Physics, General Physics and Astronomy, Plasma, Electron, 01 natural sciences, 010305 fluids & plasmas, Ion, Physics::Plasma Physics, Ionization, 0103 physical sciences, Femtosecond, Physics::Space Physics, Radiative transfer, Atomic physics, 010306 general physics, Spectroscopy, Electron ionization
Abstract: Electron-ion collisional dynamics is of fundamental importance in determining plasma transport properties, nonequilibrium plasma evolution, and electron damage in diffraction imaging applications using bright x-ray free-electron lasers (FELs). Here we describe the first experimental measurements of ultrafast electron impact collisional ionization dynamics using resonant core-hole spectroscopy in a solid-density magnesium plasma, created and diagnosed with the Linac Coherent Light Source x-ray FEL. By resonantly pumping the $1s\ensuremath{\rightarrow}2p$ transition in highly charged ions within an optically thin plasma, we have measured how off-resonance charge states are populated via collisional processes on femtosecond time scales. We present a collisional cross section model that matches our results and demonstrates how the cross sections are enhanced by dense-plasma effects including continuum lowering. Nonlocal thermodynamic equilibrium collisional radiative simulations show excellent agreement with the experimental results and provide new insight on collisional ionization and three-body-recombination processes in the dense-plasma regime.
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