TY  - JOUR
AU  - Budewig, Laura
AU  - Son, Sang-Kil
AU  - Santra, Robin
TI  - Electron-cloud alignment dynamics induced by an intense X-ray free-electron laser pulse: a case study on atomic argon
JO  - Communications Physics
VL  - 7
IS  - 1
SN  - 2399-3650
CY  - London
PB  - Springer Nature
M1  - PUBDB-2024-04674
SP  - 363
PY  - 2024
AB  - In an intense X-ray free-electron laser (XFEL) pulse, atoms are sequentially ionised by multiple X-ray photons. Photoionisation generally induces an alignment of the electron cloud of the produced atomic ion regarding its orbital-angular-momentum projections. However, how the alignment evolves during sequential X-ray multi-photon ionisation accompanied by decay processes has been unexplored. Here we present a theoretical prediction of the time evolution of the electron-cloud alignment of argon ions induced by XFEL pulses. To this end, we calculate state-resolved ionisation dynamics of atomic argon interacting with an intense linearly polarised X-ray pulse, which generates ions in a wide range of charge states with non-zero orbital- and spin-angular momenta. Employing time-resolved alignment parameters, we predict the existence of non-trivial alignment dynamics during intense XFEL pulses. This implies that even if initially the atomic electron cloud is perfectly spherically symmetric, X-ray multi-photon ionisation can lead to noticeable reshaping of the electron cloud.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:001351613500001
DO  - DOI:10.1038/s42005-024-01852-x
UR  - https://bib-pubdb1.desy.de/record/610668
ER  -