A pulse technique for the measurement of the ratio of diffusion to mobility for electron swarms in gases at high E/N

Abstract

A pulse technique has been developed for the measurement of the ratio of radial diffusion coefficient to mobility (Dr/ mu ) for electrons in gases. Measurements have been made in carbon dioxide for the experiment range 14<E/N<5650 Td, where E/N is the ratio of electric field to gas number density. The magnitude of Dr/ mu increases with increasing E/N; values vary from 0.85 V to 18.0 V and show good agreement with the results of Lakshminarasimha et al. (1974) obtained by using a steady-state technique for E/N up to 1553 Td. A Monte Carlo simulation of the present experimental range shows that the equilibrium conditions exist after the electrons have travelled a short distance within the gap.