Langevin Equation and the ac Conductivity of NonMaxwellian Plasmas
Abstract
The use of the Langevin equation {dvdt+gv=(qm)[E_{0}e^{iωt}+(vc)×H]} to describe the electrical conductivity of a nonMaxwellian plasma (a weakly ionized gas in which the average electron collision frequency is temperature dependent) may be in error unless it is understood that the dissipative term, g, is complex. In the limiting cases of either high or low pressures the imaginary part of g is negligible. The real and imaginary parts of g are evaluated for these limiting cases, for four different gases; air, helium, Maxwellian gas, and water. The real part of g is shown to be the average collision frequency multiplied by a numerical factor, the size of which depends on the nature of the gas and the pressure limit.
 Publication:

Physical Review
 Pub Date:
 April 1959
 DOI:
 10.1103/PhysRev.114.29
 Bibcode:
 1959PhRv..114...29M