Experimental verification of the theory on the inverse Smith–Purcell effect at a submillimeter wavelength

Abstract

The inverse Smith–Purcell effect is a candidate for laser-driven linacs utilizing the interaction between laser light and an electron beam traveling just in front of a metallic grating. We have performed experiments to study electron energy spread as a function of electron beam position above the grating. A submillimeter wave laser (CH3F, 496 μm) is used as a driving source. It is found that the energy spread characteristics show exponential decay of the interaction strength (field intensity) in the direction perpendicular to the grating surface, as a classical theory on the effect predicts.