Lee Jong Won, Kang Gyeongbo, Kim Minju, Kim Minseok, Park Sang Han, Kwon Soonnam, Yang Seonghyeok, Cho Byoung Ick
Department of Physics and Photon Science, GIST, Gwangju 61005, Republic of Korea.
Pohang Accelerator Laboratory, Pohang, Gyeongbuk 37673, Republic of Korea.
J Synchrotron Radiat. 2020 Jul 1;27(Pt 4):953-958. doi: 10.1107/S160057752000524X. Epub 2020 May 19.
Free-electron laser pulse-based X-ray absorption spectroscopy measurements on warm dense copper are presented. The incident X-ray pulse energies were measured with a detector assembly consisting of a photocathode membrane and microchannel plates, and the transmitted energies were measured simultaneously with a photodiode detector. The precision of the absorption measurements was evaluated. For a warm dense copper foil irradiated by an intense femtosecond laser pulse, the enhanced X-ray absorption below the L-edge, followed by the rapid evolution of highly excited Fermi liquid within a picosecond, were successfully measured. This result demonstrates a unique capability to study femtosecond non-equilibrium electron-hole dynamics in extreme states of matter.
本文介绍了基于自由电子激光脉冲的热密铜的X射线吸收光谱测量。入射X射线脉冲能量由一个由光电阴极膜和微通道板组成的探测器组件测量，而透射能量则由光电二极管探测器同时测量。评估了吸收测量的精度。对于由强飞秒激光脉冲辐照的热密铜箔，成功测量到了L边以下增强的X射线吸收，以及在皮秒内高度激发费米液体的快速演化。这一结果证明了在极端物质状态下研究飞秒非平衡电子-空穴动力学的独特能力。
