ELECTRON BUNCHING CHARACTERISTICS IN THE GYROTRON TRAVELING-WAVE AMPLIFIER WITH TWO-STAGE INTERACTION CIRCUIT

Based on a simplified model, an analytic theory describing the bunching of the electron beam in a gyrotron traveling wave tube (gyro-TWT) with two-stage interaction circuit is presented. The analytic formulas of the traveling-wave bunching parameter, ballistic bunching parameter, and the density of the bunching beam are obtained. The bunching procedures corresponding to different harmonic operations are studied. It is shown that the maximum of harmonic component depends on the ratio of the harmonic number in the output stage to that in the input stage, not on their absolute values.