Investigation of changes in field electron emission characteristics of industrial fine-grained graphite when operated in an argon atmosphere up to 10–2 Pa

Abstract

Abstract Studying of field electron emission properties of carbon cathodes operating under technical vacuum conditions is a promising scientific field. Massive cathode made of commercial fine-grained graphite of MG (Russian abbreviation) grade is being investigated. Experiments on obtaining current-voltage characteristics and long-term testing are being carried out. The emitter made of fine-grained graphite demonstrates good emission properties under technical vacuum conditions. Carbon cathode is capable of operating at pressures up to 2×10–2 Pa. Increased pressure in the vacuum chamber leads to deterioration of cathode emission properties. Electric field enhancement factors were calculated for all stages of studies. Analysis of experimental data demonstrates decrease in enhancement factor due to ion bombardment of cathode surface during exploitation. This results in higher electric field for operation of investigated graphite cold cathodes.