Measurement of electron swarm coefficients in chlorine and its mixtures with nitrogen

Abstract

We have measured the electron drift velocity, density-normalized longitudinal diffusion and effective ionization coefficients for electrons in Cl2 and Cl2–N2 mixtures over the combined E/N range from 3 to 450 Td, using a pulsed Townsend apparatus especially designed to withstand the action of corrosive gases. Our measurements for the electron drift velocity and the effective ionization coefficient are compared with the only two previous measurements available, one of them indirect. In view of the present incompleteness and uncertainty in the electron collision cross section set for Cl2, Cl2–N2 mixtures with Cl2 contents from 1% to 80% have been measured in the aim of shedding more light into the completeness and reliability of the cross section set by testing the cross sections derived for pure Cl2 with those of the Cl2–N2 mixture for which the cross sections for N2 are well known.