Collision frequencies for use in the continuum momentum equations applied to the lower ionosphere

Abstract

The collision frequencies for use in the continuum momentum equation are found for low energy electrons in N 2 and O 2 and for the polarization interaction between ions and neutral molecules; consideration is given to the case of low-frequency transport phenomena in a weakly ionized ionospheric plasma. For the electrons, the method of assuming a displaced Maxwellian velocity distribution function is compared with the method of obtaining transport coefficients from the linearized Boltzmann equation. It is found that the method of assuming a displaced Maxwellian distribution for the electrons is not a good approximation, and reasons why this is so are given.