Experimental study of surface-wave oscillator with different electron beam forms

Abstract

We experimentally studied intense terahertz-wave generation based on a W-band (0.1 THz) surface-wave oscillator (SWO) using annular electron beams with different beam forms. In order to generate different beam forms, we prepare two-type anodes with open beam limiter and close beam limiter. The electron beam is shaped by the close beam limiter, and the thickness becomes thinner than that of a non-shaped beam with the open limiter. The electronic efficiency of SWO with the shaped beam is improved in comparison to that with non-shaped beam, and maximum efficiency is about 1% for 0.1 THz radiation.