Calculated Values of the Parameters of Noble Gas Discharges

Molar properties of gaseous discharges are determined by the transport cross section which is expressible in terms of the phase shifts defined in electron-atom scattering theory.σₜ(v) was calculated for helium, neon, and argon using values of phase shifts η₀ to η₆ derived by Westin from existing scattering data. Druyvesteyn distribution functions were calculated for E/p from 0.1 to 1.0. Average values were then calculated for collision frequency, drift velocity, diffusion coefficient, and average energy.Also, collision frequency and elastic energy loss were calculated using Maxwell distributions for kTₑ up to 10 ev. These calculations are particularly useful at very low energy, where extrapolation of phase shifts is more reliable than of the experimental data. Values of σₜ are compared with those of Barbiere (taken from direct scattering data); values of drift velocity are somewhat lower than Nielsen's data.