Transport Property of Electrons in Gases under Electric Field 1. Lateral Diffusion Coefficient

Abstract

The well known formula of isotropic diffusion coefficient D v of electrons does not give exact values of lateral diffusion coefficient D T under an electric field. D v implies the ensemble average of the instantaneous probability of diffusion, while D T is obtained as the time average of diffusion flux. The cause of the discrepancy between D v and D T is the change of the collision frequcncy within respective flights of electrons due to the electric field. Problems concerning D v and D T are made clear from relevant quantities calculated by the analytical method and by the Monte-Carlo simulation for various model cross sections.