Experimental study of trapped electrons influence on the helical electron beam parameters for millimeter wave range gyrotrons

Abstract

The basic properties (velocity spread, average oscillatory energy and oscillatory velocity distribution function) of helical electron beams (HEB) formed in the magnetron-injection gun (MIG) of powerful millimeter wave range gyrotrons are investigated experimentally at the presence of electrons, reflected by the magnetic mirror and locked in adiabatic trap. Guns for 83 GHz, 110 GHz, 140 GHz and 170 GHz, 1 MW power level gyrotrons, forming quasilaminar, regularly intersecting, mixed and boundary HEB (between quasilaminar and regularly intersecting HEB) are considered. The results of the experiments show that the trapped electrons significantly affect the beam parameters.