Suppression of thermal nanoplasma emission in clusters strongly ionized by hard x-rays
: Kumagai Yoshiaki, Jurek Zoltan, Xu Weiqing, Saxena Vikrant, Fukuzawa Hironobu, Motomura Koji, Iablonskyi Denys, Nagaya Kiyonobu, Wada Shin-ichi, Ito Yuta, Takanashi Tsukasa, Yamada Shuhei, Sakakibara Yuta, Hiraki Toshiyuki Nishiyama, Umemoto Takayuki, Patanen Minna, Bozek John D, Dancus Ioan, Cernaianu Mihail, Miron Catalin, Bauer Tobias, Mucke Melanie, Kukk Edwin, Owada Shigeki, Togashi Tadashi, Tono Kensuke, Yabashi Makina, Son San-Kil, Ziaja Beata, Santra Robin, Ueda Kiyoshi
Publisher: IOP PUBLISHING LTD
: 2021
: Journal of Physics B: Atomic, Molecular and Optical Physics
: JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS
: J PHYS B-AT MOL OPT
: ARTN 044001
: 54
: 4
: 16
: 0953-4075
DOI: https://doi.org/10.1088/1361-6455/abd878
: https://iopscience.iop.org/article/10.1088/1361-6455/abd878
Using electron and ion spectroscopy, we studied the electron and nuclear dynamics in similar to 50 000-atom large krypton clusters, following excitation with an intense hard x-ray pulse. Beyond the single pulse experiment, we also present the results of a time-resolved, x-ray pump-near-infrared probe measurement that allows one to learn about the time evolution of the system. After core ionization of the atoms by x-ray photons, trapped Auger and secondary electrons form a nanoplasma in which the krypton ions are embedded, according to the already published scenario. While the ion data show expected features, the electron emission spectra miss the expected pump-probe delay-dependent enhancement except for a slight enhancement in the energy range below 2 eV. Theoretical simulations help to reveal that, due to the deep trapping potential of the ions during the long time expansion accompanied by electron-ion recombination, thermal emission from the transient nanoplasma becomes quenched.
