Simulating a multibeam electron-optical system of a transparent mini-TWT

The results are presented of simulating a 36-beam electron stream shaping system for a ´transparent´ mini-TWT built on permanent magnets. The physical nature of limitations on the multibeam electron stream transmission through thin (0.4 mm) transit channels has been studied. The level of the stream transmission is determined by the amplitude of the magnetic field transverse component in a gap between the poles of a magnetic system. Optimization criteria for such magnetic systems are proposed. A complete delivery of the multibeam stream to the collector is provided.