Experimental study of intense helical electron beams with trapped electrons

Abstract

The velocity spread and the average oscillatory energy of intense helical beams of gyrotrons are studied experimentally in the presence of electrons reflected by the magnetic mirror and locked into the adiabatic trap. The resutls of the experiments show that the trapped electrons significantly affect the beam parameters, especially in systems forming quasi-laminar beams. Modifications of magnetron-injection guns (MIG), in which some relaxation of the reflected electron effect is achieved, are considered.