Diffraction and spread of the electron beam with transverse emittance ε in standing wave of light

Abstract

Abstract Electron beam propagation in the light standing wave for both high and low intensity has been calculated by Thermal Wave Model (TWM). The electrons are scattered in high light intensity, as described in the Kapitza-Dirac effect. Numerical results show the significance of the transverse beam emittance to the quality of the diffraction pattern. In low light intensity, the electrons cannot be scattered, but we demonstrate that only the phase of the electron beam is shifted. Theoretical results show that the transverse average beam momentum σp varies while the effective beam σx size remains. The TWM phase-space distributions of the electron beam are given and show the influence of the transverse emittance ε on the beam spreading in this situation. Our works show the possibility of using lasers to design electron beam phase plates and quantify the transverse coherence of electron beams.