Laser-Aided Measurement of Electric Field Distribution in a Hollow Cathode Discharge

Abstract

In a helium hollow cathode discharge, a laser-induced fluorescence (41D→21P) due to the forbidden excitation (21S→41D, 397.2 nm) which is caused by the Stark effect was observed as well as the same fluorescence due to a collisional transfer via the allowed excitation (21S→41P, 396.5 nm). A new method is described to measure electric field strength in a region of the cathode surfaces from the intensity ratio of respective fluorescences. Electric field intensity distribution is measured in plane-parallel hollow cathode discharge by using this method in a range from 0.5 to 3.9 kV/cm in the dark space. The detection limit is briefly discussed.