Average energy expended per ion pair in liquid xenon

摘要: Measurements were made of the average energy W per ion pair formed in liquid xenon by internal-conversion electrons from 207Bi. Voltage pulses observed resulting electron collection either or a gaseous mixture argon (95 percent) and methane (5 percent). The relative pulse heights for two materials determine ratio values. Using known mixture, liquid-xenon 15.6 + - 0.3 eV was obtained. This value is considerably smaller than gas-phase values, 21.5 21.9 eV. For interpretation, Platzman's energy-balance equation adapted to liquids, assuming conduction-band picture. Theoretical values thus calculated agree well with experiment.