Real-time observation of disintegration processes within argon clusters ionized by a hard-x-ray pulse of moderate fluence

Yoshiaki Kumagai (1) , Zoltan Jurek (2) , Weiqing Xu (3) , Hironobu Fukuzawa (1) , Koji Motomura (1) , Denys Iablonskyi (1) , Kiyonobu Nagaya (4) , Shin-Ichi Wada (4) , Subhendu Mondal (1) , Tetsuya Tachibana (1) , Yuta Ito (1) , Tsukasa Sakai (5) , Kenji Matsunami (5) , Toshiyuki Nishiyama (5) , Takayuki Umemoto (6) , Christophe Nicolas (7) , Catalin Miron (7, 8) , Tadashi Togashi (9) , Kanade Ogawa (4) , Shigeki Owada (4) , Kensuke Tono (4) , Makina Yabashi (4) , Sang-Kil Son (2) , Beata Ziaja (2) , Robin Santra (2) , Kiyoshi Ueda (4)

1 Tohoku University [Sendai]
2 DESY - Deutsches Elektronen-Synchrotron [Hamburg]
3 BUAA - Beihang University
4 RIKEN - RIKEN - Institute of Physical and Chemical Research [Japon]
5 Kyoto University
6 Hiroshima University
7 SSOLEIL - Synchrotron SOLEIL
8 LIDYL - Laboratoire Interactions, Dynamiques et Lasers (ex SPAM)
9 JASRI - Japan Synchrotron Radiation Research Institute [Hyogo]

We present a time-resolved study of disintegration within atomic clusters ionized by a hard-x-ray pulse of moderate fluence. It was performed with electron and ion spectroscopy, and complemented by theoretical simulations. The expanding clusters were probed with a near-infrared (NIR) laser pulse over a range of pump-probe delays from −4 to 10 ps. In addition to an increasing number of singly charged atomic ions, originating from the ionization of Rydberg atoms formed through electron-ion recombination, we observe a decrease of oligomer yields. The latter is due to the interaction of oligomers with the NIR probe pulse, leading to their dissociation. At time delays between −1 and 2 ps, efficient absorption of the NIR laser energy occurs, even though the NIR intensity is too low to trigger tuneling ionization of Ar atoms. Our observations are similar to earlier observations of the fragmentation behavior of clusters excited by soft-x-ray pulses. This indicates that the relaxation dynamics of x-ray-excited nano-objects are universal over a wide range of excitation photon energies.

Domaines: Physique [physics]

Yoshiaki Kumagai, Zoltan Jurek, Weiqing Xu, Hironobu Fukuzawa, Koji Motomura, et al.. Real-time observation of disintegration processes within argon clusters ionized by a hard-x-ray pulse of moderate fluence. Physical Review A, 2020, 101 (2), ⟨10.1103/PhysRevA.101.023412⟩. ⟨hal-02864557⟩