Ionization current measurements in gases using an internal tritium β source

Abstract

The β-particles from tritium have been used as an energy source for the ionization of gaseous xenon, argon, neon, and oxygen. The ion currents determined from an ionization chamber study of T₂-gas mixtures enable the energy required to form an ion pair (W value) to be calculated for these gases. A series of fluorocarbon gases have also been studied and their W values determined for the first time. Consideration of the energy transfer (Jesse) effect limits the usefulness of this technique to gases of ionization potential of less than 15.5 eV.