Effect of the Pressure of Alcohol Vapour on the Operation of the Fast Geiger-Müller Counter

Abstract

As a result of the theoretical researches of Montgomery and Montgomery¹, Stever², Korff and Present³, the operation of the fast Geiger-Müller counter is now very fully understood. In such a counter the discharge produced by a single ionizing particle is quenched by the following three processes: (a) The formation of a positive ion sheath which so reduces the field in the neighbourhood of the wire that further ionization by collision cannot take place. (b) The prevention of the emission of photo-electrons from the cathode by the rapid absorption of photons by the polyatomic vapour followed by the pre-dissociation of the organic molecule. Processes (a) and (b) are of especial importance in the quenching of the initial discharge. (c) The prevention of the secondary emission of electrons from the cathode by positive ion bombardment by the predissociation of the organic molecule. Korff and Present have shown that the stopping of multiple discharges is due to process (c).