Electron drift and attachment in CHF3 and its mixtures with argon

Measurements are reported of the electron drift velocity, w, in CHF3 gas and in its mixtures with argon. The E/N dependence of w in the mixtures exhibits regions of distinct negative differential conductivity. A small electron attachment rate constant (∼13×10−14 cm3 s−1 for density-reduced electric fields, E/N<50×10−17 V cm2) has been measured, which may be due to impurities.