A Computational Scheme of Propagator Method for Moment Equations to Derive Real-Space Electron Transport Coefficients in Gas Under Crossed Electric and Magnetic Fields

A numerical technique to calculate real-space electron transport coefficients in gas under crossed electric and magnetic fields (E × B fields) by the propagator method (PM) was newly developed. Components of a centroid drift velocity vector of an electron swarm and its diffusion coefficients defined in the E, B, and E × B directions were calculated by applying the PM stepwise to the zeroth-, first-, and second-order x, y, and z spatial moment equations derived from the Boltzmann equation. The results calculated for SF
₆
at N = 10
²²
m
^-3
in E/N and B/N ranges of 100-1000 Td and 100-1000 Hx, respectively, agreed with those obtained by Monte Carlo simulations with discrepancies of a few percent. The Hall deflection of the drift velocity vector and the direction dependence of the diffusion coefficients were appropriately reproduced. A relaxation scheme developed for quick convergence of the electron velocity distribution function was effective also in the relaxations of the first- and second-order spatial moment distribution functions. A prototype of the PM as a calculation scheme to derive a set of electron transport coefficients necessary for fluid model simulations of magnetized plasmas was established.