Further studies of electron emission areas on electropolished copper surfaces in vacuum

Abstract

A lead transfer technique described in an earlier publication has been applied to the problem of locating electron emission areas on broad−area electrodes in vacuum. The objective of this work is to identify and analyze microscopic emission areas on electropolished copper and to determine their Fowler−Nordheim characteristics. The results suggest that insulating inclusions play an important part in the emission from such surfaces and indeed have emission characteristics which are similar to those expected for metallic emitters.