• R.K. Li, H. Chen, Q. Du, T. Du, Y.-C. Du, Hua, J.F. Hua, W.-H. Huang, X. H. Lu, J. Shi, C.-X. Tang, H. S. Xu, L.X. Yan
  TUB, Beijing

Re­cent years have wit­nessed rapid ad­vances of MeV ul­tra­fast elec­tron diffrac­tion (UED), in which high qual­i­ty, ul­tra­short, MeV elec­tron puls­es from a pho­to­cath­ode RF gun are em­ployed as probes for ul­tra­fast struc­tural dy­nam­ics. We've built a pro­to­type MeV UED sys­tem at the Ac­cel­er­a­tor Lab­o­ra­to­ry of Ts­inghua Uni­ver­si­ty, op­ti­mized the the elec­tron pulse pa­ram­e­ters as well as hard­ware per­for­mances, and achieved high qual­i­ty sin­gle-shot diffrac­tion pat­terns. More­over, MeV UED can be op­er­at­ed in a so-called 'con­tin­u­ous­ly time-re­solved (CTR)' mode, in which an RF de­flect­ing cav­i­ty streaks the elec­tron pulse thus each diffrac­tion pat­tern con­sti­tutes an 'atom­ic movie'. We re­port our ex­per­i­men­tal progress on MeV UED in this paper.