Generalised full wave theory for energy-dependent collision frequencies

Abstract

Equations are derived to describe the propagation of a plane electromagnetic wave through a magneto-ionic medium in which the collision frequency of mono-energetic electrons is proportional to the electron energy. It is shown that no essentially new features are introduced into the results of full-wave calculations by the use of the generalised theory and that a suitable choice of effective classical collision frequency gives numerical results in good agreement with the more complicated theory. For an ionosphere at temperature T and for frequencies less than 100 kc/s the effective collision frequency, Veff, is related in the following way to the collision frequency, vM, appropriate to mono-energetic electrons with energy kT.Veff ≏ 3/2 vM when ωH ≪ vM and Veff ≏ 5/2 vM when ωH ≫ vM; at higher frequencies ωH is replaced by ω, the angular wave frequency.