K. Maeda et al., DIFFUSION TENSOR IN ELECTRON-TRANSPORT IN GASES IN A RADIOFREQUENCY FIELD, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics, 55(5), 1997, pp. 5901-5908
Electron transport theory in gases in a radio-frequency field is devel
oped in the hydrodynamic regime from the density gradient expansion me
thod of the Boltzmann equation. Swarm parameters for the radio-frequen
cy (rf) field with periodic time modulation are derived as functions o
f both reduced effective field strength and reduced angular frequency
from the time dependent velocity distribution function. The rf electro
n transport in phase space is analyzed from the series of governing eq
uations by a direct numerical procedure (DNP). Electron velocity distr
ibution function and corresponding swarm parameters obtained from DNP
agree with those of the Monte Carlo simulation in the frequency range
10-200 MHz at 10 Td for Reid's inelastic ramp model gas. The temporal
modulation of the ensemble average of energy and the diffusion tensor
an discussed. The appearance of the anomalous time behavior of the lon
gitudinal diffusion coefficient is discussed in particular detail, and
we provide an explanation of the observed effect.