The Ratio of the Lateral Diffusion Coefficient to Mobility for Electrons in Argon at 294 K

Abstract

The ratio of the lateral diffusion coefficient to mobility (D_T/μ) for electrons in argon has been measured at 294 K in the range 0.001 ≤ E/N (Td) ≤ 0.1 using pressures in the range 309–1171 kPa. The total error in the best-estimate values is estimated to be less than ± 2 % for E/N ≤ 0.0035 Td and less than ± 1.5 % for E/N ≥ 0.004 Td. A discussion is given of the design of a Townsend–Huxley diffusion experiment in light of recent theoretical work on the influence of material boundaries on diffusing streams of charged particles and of the effects on the measurements of multiple scattering and dimer formation.