Generation of ultrahigh-brightness pre-bunched beams from a plasma cathode for X-ray free-electron lasers.

ABSTRACT: The longitudinal coherence of X-ray free-electron lasers (XFELs) in the self-amplified spontaneous emission regime could be substantially improved if the high brightness electron beam could be pre-bunched on the radiated wavelength-scale. Here, we show that it is indeed possible to realize such current modulated electron beam at angstrom scale by exciting a nonlinear wake across a periodically modulated plasma-density downramp/plasma cathode. The density modulation turns on and off the injection of electrons in the wake while downramp provides a unique longitudinal mapping between the electrons' initial injection positions and their final trapped positions inside the wake. The combined use of a downramp and periodic modulation of micrometers is shown to be able to produces a train of high

SUBMITTER: Xu X 

PROVIDER: S-EPMC9188572 | biostudies-literature | 2022 Jun

REPOSITORIES: biostudies-literature