Secondary electron emission of dielectric materials under high emperature condition

Secondary electron emission (SEE) coefficients of alumina, sapphire; Si0₂, and MgO were measured by using a SEM with short-pulsed electron beam under room and high temperatures. An appreciable reduction in the SEE coefficients with increasing temperature was confirmed, except for sapphire. In addition, it was found that at room and high temperature SEE coefficients of alumina increased with purity and grain size.