Theory of the density dependence of electron drift velocity in gases

We present a quantum-mechanical theory of the electron drift speed W in a gas in a field at low E/N and relatively high pressures. It is able to give a quantitative interpretation of the experimental results, as regards the dependence of W on both the gas number density and the gas temperature. As an application, we make a comparison between theory and experiment in He, H₂, N₂, and Ar.