EXPERIMENTAL-VERIFICATION OF THE THEORY ON THE INVERSE SMITH-PURCELL EFFECT AT A SUBMILLIMETER WAVELENGTH

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-mu-m) 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.