Experimental Measurements of Gas Pumping in an Argon Discharge

Abstract

Measurements have been made of the pressure difference between the cathode and anode bottles of a standard cw argon ion laser tube, with a positive column of 30-cm length and 1.25-mm radius. At several amperes current the pressure difference (anode minus cathode) is approximately constant at 0.25 Torr below 1.2 Torr, and is inversely proportional to pressure above that pressure. The results are compared with the predictions of various theories. The theory presented in the preceding paper accurately predicts both the magnitude of the pumping effect and its dependence upon pressure and current.