Excess Electrons and Positive Charge Carriers in Liquid Methane. I

Abstract

Abstract The drift velocities of radiation-induced excess electrons and positive charge carriers in liquid methane were measured at different electric field strengths and several temperatures. For the excess electrons the drift velocity increases up to 1.5 kV cm-1 proportional to the electric field strength and a mobility of (400±50) cm2 V-1 s-1 at T = 111 °K was obtained. Above 1.5 kV cm-1 the drift velocity varies with E½. The temperature coefficient of the mobility is negative. For the positive charge carriers the measurements were carried out up to electric field strengths of 50 kV cm-1 and the drift velocity remained proportional to the field giving a mobility of (2.5 ± 0.5) · 10-3 cm2 V-1 s-1 at 7 = 111 °K. The mobility increased with increasing temperature. The reaction of excess electrons with oxygen was also studied and a rate constant of 8.4 · 1011 l mole-1 s-1 was obtained.