Secondary electron ejection from metal surfaces by metastable atoms. I. Measurement of secondary emission coefficients using a crossed beam method

Abstract
A crossed beam technique has been used to determine secondary electron emission coefficients for He(21S), He(23S), Ne(3P0.2) and Ar(3P0.2) metastable atoms incident with thermal energy on atomically clean cadmium and contaminated stainless steel surfaces. The secondary emission coefficients for the atomically clean surface were in all cases found to be less than 0.5, but for the contaminated surfaces values in excess of 0.5 were measured. Mechanisms are suggested to account for the observed large values.