TY  - JOUR
AU  - Engel, Robin Y.
AU  - Alexander, Oliver
AU  - Atak, Kaan
AU  - Bovensiepen, Uwe
AU  - Buck, Jens
AU  - Carley, Robert
AU  - Cascella, Michele
AU  - Chardonnet, Valentin
AU  - Chiuzbaian, Gheorghe Sorin
AU  - David, Christian
AU  - Döring, Florian
AU  - Eschenlohr, Andrea
AU  - Gerasimova, Natalia
AU  - de Groot, Frank
AU  - Guyader, Loïc Le
AU  - Humphries, Oliver S.
AU  - Izquierdo, Manuel
AU  - Jal, Emmanuelle
AU  - Kubec, Adam
AU  - Laarmann, Tim
AU  - Lambert, Charles-Henri
AU  - Lüning, Jan
AU  - Marangos, Jonathan P.
AU  - Mercadier, Laurent
AU  - Mercurio, Giuseppe
AU  - Miedema, Piter S.
AU  - Ollefs, Katharina
AU  - Pfau, Bastian
AU  - Rösner, Benedikt
AU  - Rossnagel, Kai
AU  - Rothenbach, Nico
AU  - Scherz, Andreas
AU  - Schlappa, Justine
AU  - Scholz, Markus
AU  - Schunck, Jan O.
AU  - Setoodehnia, Kiana
AU  - Stamm, Christian
AU  - Techert, Simone
AU  - Vinko, Sam M.
AU  - Wende, Heiko
AU  - Yaroslavtsev, Alexander A.
AU  - Yin, Zhong
AU  - Beye, Martin
TI  - Electron Population Dynamics in Resonant Non-Linear X-ray Absorption in Nickel at a Free-Electron Laser
JO  - Structural dynamics
VL  - 10
IS  - 5
SN  - 2329-7778
CY  - Melville, NY
PB  - AIP Publishing LLC
M1  - PUBDB-2023-04604
M1  - arXiv:2211.17008
SP  - 054501
PY  - 2023
AB  - Free-electron lasers provide bright, ultrashort, and monochromatic X-ray pulses, enabling novel spectroscopic mea-surements not only with femtosecond temporal resolution: The high fluence of their X-ray pulses can also easily enterthe regime of non-linear X-ray-matter interaction. Entering this regime necessitates a rigorous analysis and reliableprediction of the relevant non-linear processes for future experiment designs. Here we show non-linear changes in theL3-edge absorption of metallic nickel thin films, measured with fluences up to 60 J/cm2. We present a simple but pre-dictive rate model that quantitatively describes spectral changes based on the evolution of electronic populations withinthe pulse duration. Despite its simplicity, the model reaches good agreement with experimental results over more thanthree orders of magnitude in fluence, while providing a straightforward understanding of the interplay of physical pro-cesses driving the non-linear changes. Our findings provide important insights for the design and evaluation of futurehigh-fluence free-electron laser experiments, and contribute to the understanding of non-linear electron dynamics inX-ray absorption processes in solids at the femtosecond timescale.
LB  - PUB:(DE-HGF)16
C6  - 37841290
UR  - <Go to ISI:>//WOS:001082350300001
DO  - DOI:10.1063/4.0000206
UR  - https://bib-pubdb1.desy.de/record/587908
ER  -