TY  - JOUR
A1  - Niozu, Akinobu
A1  - Kumagai, Yoshiaki
A1  - Fukuzawa, Hironobu
A1  - Naomichi, Yokono
A1  - You, Daehyun
A1  - Saito, Shu
A1  - Luo, Yu
A1  - Kukk, Edwin
A1  - Cirelli, Claudio
A1  - Rist, Jonas
A1  - Vela-Pérez, Isabel
A1  - Kameshima, Takashi
A1  - Joti, Yasumasa
A1  - Motomura, Koji
A1  - Togashi, Tadashi
A1  - Owada, Shigeki
A1  - Katayama, Tetsuo
A1  - Tono, Kensuke
A1  - Yabashi, Makina
A1  - Young, Linda
A1  - Matsuda, Kazuhiro
A1  - Bostedt, Christoph
A1  - Ueda, Kiyoshi
A1  - Nagaya, Kiyonobu
T1  - Relation between inner structural dynamics and ion dynamics of laser-heated nanoparticles
T2  - Physical review. X
N2  - When a nanoparticle is irradiated by an intense laser pulse, it turns into a nanoplasma, a transition that is accompanied by many interesting nonequilibrium dynamics. So far, most experiments on nanoplasmas use ion measurements, reflecting the outside dynamics in the nanoparticle. Recently, the direct observation of the ultrafast structural dynamics on the inside of the nanoparticle also became possible with the advent of x-ray free electron lasers (XFELs). Here, we report on combined measurements of structural dynamics and speeds of ions ejected from nanoplasmas produced by intense near-infrared laser irradiations, with the control of the initial plasma conditions accomplished by widely varying the laser intensity (9×1014  W/cm2 to 3×1016  W/cm2). The structural change of nanoplasmas is examined by time-resolved x-ray diffraction using an XFEL, while the kinetic energies of ejected ions are measured by an ion time-of-fight method under the same experimental conditions. We find that the timescale of crystalline disordering in nanoplasmas strongly depends on the laser intensity and scales with the inverse of the average speed of ions ejected from the nanoplasma. The observations support a recently suggested scenario for nanoplasma dynamics in the wide intensity range, in which crystalline disorder in nanoplasmas is caused by a rarefaction wave propagating at a speed comparable with the average ion speed from the surface toward the inner crystalline core. We demonstrate that the scenario is also applicable to nanoplasma dynamics in the hard x-ray regime. Our results connect the outside nanoplasma dynamics to the loss of structure inside the sample on the femtosecond timescale.
KW  - Atomic and Molecular Physics
KW  - Plasma Physics
Y1  - 2021
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/63220
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-632208
SN  - 2160-3308
VL  - 11
IS  - 3, art. 031046
SP  - 1
EP  - 12
PB  - American Physical Society
CY  - College Park, Md.
ER  -