Generation and Formation of Axially Symmetrical Tubular Electron Beam in a Cold Metal Secondary-Emission Cathode Magnetron Gun—Part I: Experiment

This paper presents a new design of a cold metal (Cu, Al, and stainless steel) secondary-emission cathode magnetron gun for the generation of axially symmetrical tubular electron beam with a current from units to tens of amperes and the following input parameters: 1) dc longitudinal magnetic field 1500 G; 2) pulsed voltage ranging from 5 to 100 kV; 3) pulse length of 2 × 10 μs-2 × 100 ns; and 4) pulse-repetition rate between 10 and 50 Hz. The results of the experimental investigations dealing with feature generation and formation of periodical electron bunches are presented. It is shown that an efficiency of secondary-electron multiplication depends on the shape and parameters of an anode voltage pulse and the features of a static magnetic field distribution as well as a material of the cold secondary-emission cathode.