The ionisation and attachment coefficients in carbon tetrafluoride

Abstract

The ionisation alpha /p, electron attachment eta /p and effective ionisation alpha /p (=( alpha /p)-( eta /p)) coefficients were measured by the steady-state Townsend method for 41<or approximately=E/p<or approximately=206 V cm-1 Torr-1, where p is the gas pressure reduced to 20 degrees C. The results show that the values of alpha /p, eta /p and alpha /p are in good agreement with those of Bozin and Goodyear (1968) for E/p<or approximately=90 V cm-1 Torr-1. For larger E/p, which the present work is the first to report, the value of these parameters is found to connect, and vary, smoothly with that at lower E/p. The limiting E/p at which alpha /p= eta /p is determined to be 46.5 V cm-1 Torr-1. The value of the total secondary coefficient is measured for a limited range of E/p=120-206 V cm-1 Torr-1 and is found to assume a value of about 1*10-5 almost independent of E/p.