Focusing of the Electron Beam Generated by a Forevacuum Plasma Source With a Multichannel Emission Electrode

For a forevacuum plasma electron source, a method for ensuring effective magnetic focusing of an electron beam generated using a multichannel emission electrode is considered, which consists in reducing spherical aberrations with a radial arrangement of emission channels. The results of measurements of the diameter, current, and power density of the electron beam are presented. A non-monotonic change in the beam diameter and power density with an increase in the radial position of the emission channels is demonstrated. Thanks to the conducted research, focusing of a beam with a diameter in the crossover of 0.7 mm was ensured for 16 emission channels at an accelerating voltage of 20 kV.