Electron capture and loss in electron swarm experiments

Abstract

The effect of capture and subsequent loss of electrons upon their time distribution in time-of-flight electron swarm experiments has been investigated. It is found that if the mean release time of captured electrons is much smaller than both the drift time and the time width of the electron swarm distribution, the effective diffusion coefficientD′ is given approximately by whereD is the electron diffusion coefficient in the absence of capture,w is the drift velocity, γ is the inverse release time, β is the inverse capture time and ζ=ψ/β+γ It is shown that measurements ofw andD by the steady state Townsend method should be unaffected by temporary capture processes.