Axial emission profiles and apparent secondary electron yield in abnormal glow discharges in argon

Abstract

This paper reports investigations of argon glow discharges established between flat disk electrodes, at pressure × electrode separation values between 45 Pa cm and 150 Pa cm. Parallel to the experimental studies the discharge is also described by a self-consistent hybrid model. The model uses as input data the measured electrical characteristics, this way making it possible to determine the apparent secondary electron emission coefficient. The model is verified through comparison of the measured and calculated spatial profiles of light emission, which are in good agreement for a wide range of conditions in the abnormal glow mode. Additionally, we investigate the dependence of the field reversal position on the discharge conditions and test the usual assumption that the position of the peak of emission closely coincides with the cathode fall - negative glow boundary.