Influence of the shape of accelerating electrode in the fore- vacuum plasma electron source on the maximal parame- ters of electron beam focusing

Abstract: The results devoted to the investigation of the effect of extractor shape on the diameter of electron beam generated by the forevacuum plasma source are presented. It is shown that the smallest diameter of the beam is provided by an extractor having the smallest possible diameter of the hole. It can be due to both a smaller penetration of the accelerating field into the region beyond the extractor, and a local increase in the electric field strength near the emission hole.

Keywords: focused beam, plasma source, forevacuum, beam diameter, electric field