Design of an ultrafast electron diffractometer with multiple operation modes  

作　　者：Chun-Long Hu Zhong Wang Yi-Jie Shi Chang Ye Wen-Xi Liang 胡春龙;王众;石义杰;叶昶;梁文锡(Wuhan National Laboratory for Optoelectronics(WNLO),Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]Wuhan National Laboratory for Optoelectronics(WNLO),Huazhong University of Science and Technology,Wuhan 430074,China

出　　处：《Chinese Physics B》2021年第9期194-199,共6页中国物理B（英文版）

基　　金：Project supported by the Director Fund of WNLO (Grant No. WNLOZZYJ1501);the Fundamental Research Funds for the Central Universities,HUST (Grant No. 2017KFXKJC001);the Innovation Fund of WNLO;the Fund of State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics(Grant No. T152012)

摘　　要：Directly resolving structural changes in material on the atomic scales of time and space is desired in studies of many disciplines.Ultrafast electron diffraction(UED),which combines the temporal resolution of femtosecond-pulse laser and the spatial sensitivity of electron diffraction,is an advancing methodology serving such a goal.Here we present the design of a UED apparatus with multiple operation modes for observation of collective atomic motions in solid material of various morphologies.This multi-mode UED employs a pulsed electron beam with propagation trajectory of parallel and convergent incidences,and diffraction configurations of transmission and reflection,as well utilities of preparation and characterization of cleaned surface and adsorbates.We recorded the process of electron-phonon coupling in single crystal molybdenum ditelluride following excitation of femtosecond laser pulses,and diffraction patterns of polycrystalline graphite thin film under different settings of electron optics,to demonstrate the temporal characteristics and tunable probe spot of the built UED apparatus,respectively.

关 键 词：ultrafast electron diffraction electron optics diffraction geometry structural dynamics 

分 类 号：TH122[机械工程—机械设计及理论]