Average Energy per Ion Pair for Alpha Particles in Vapours of Several Dielectric Liquids

Abstract

The W-values for alpha particles in several kinds of vapours have been determined. A cylindrical ionization chamber of inside diameter 20 cm and length 55 cm was used for measurements. Alpha particles emitted from ²¹⁰Po source entered to the ionization chamber through a collimator with mylar window. The vapours, were obtained from highly purified samples for spectroscopy. For the vapours, relative measurements with argon, nitrogen, and dried air as standard gases have been carried out. The W-values obtained within about 3 percent error for the vapours of n-hexane, cyclohexane, benzene, carbon disulphide, dichloromethane, and carbon tetrachloride were 29.1±0.5, 28.1±0.6, 30.9±0.7, 26.0±0.5, 26.8±0.5, and 28.7±0.7 eV, respectively. These W-values were somewhat large in comparison with those for electrons.