A Study of Diffraction of Probe Electron Beams by Relativistic Plasma Waves*

An electron beam based diagnostic of relativistic plasma waves used in beatwave accelerators and in intense radiation sources (undulators) is studied using numerical simulations.  Electron beam diffraction as well as bunching, filamentation, focusing were observed in the simulations.  The electron beam propagates perpendicularly through the plasma wave.  The plasma wave behaves as grating that moves with a relativistic phase velocity.  The energy and physical profiles of the original electron beam and relativistic plasma wave are compared to the characteristics of the transformed electron beam’s transverse and longitudinal profiles using numerical analyses, including Fourier Transform techniques.