A study of Ar + C2H4 and Xe + CF4 gas mixtures

Abstract

Mixtures of Ar + 40 ppm C2H4 and 50% Xe + 50%CF4 have been investigated. The spatial distributions of photoelectron clouds produced by primary scintillations on α- and β-particle tracks, as well as the distributions of photoelectron clouds due to photons from avalanches at the pin anode, have been measured for the first time. For a mixture of 50% Xe + 50%CF4, it has been shown for the first time that CF4 is a photosensitive dopant in a mixture with Xe. For a mixture of Xe + CF4 (1: 1), the maximum electron multiplication factors at the pin anode are K(β)max = 3 × 104 and K(α)max = 3 × 103 at a pressure of 1 atm (abs.) and K(β)max = 104 and K(α)max = 4 × 103 at a pressure of 10 atm (abs.)