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Electron Kinetics in the Cathode Region of a Glow Discharge and in Hollow Cathodes
Author(s) -
Valentini H.B.
Publication year - 1987
Publication title -
beiträge aus der plasmaphysik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.531
H-Index - 47
eISSN - 1521-3986
pISSN - 0005-8025
DOI - 10.1002/ctpp.19870270503
Subject(s) - electron , atomic physics , ionization , cathode , cascade , scattering , inelastic collision , physics , monte carlo method , electron scattering , inelastic scattering , chemistry , ion , nuclear physics , quantum mechanics , statistics , mathematics , chromatography
On the basis of an improved cascade model a multi‐group theory for studying the electron kinetics in the cathode region of a glow discharge and in hollow cathodes is developed. The secondary electrons newly created by ionization are taken into account. The electrons are divided in groups with respect to the interval where they were created or where they made an inelastic collision. The inelastic collisions and the forward scattering are assumed to dominate. The mean energies of two neighbouring groups are taken to be different by the ionization energy or by parts of it. For the flux densities of the various electron groups a set of ordinary first order differential equations and corresponding boundary conditions are obtained and solved for He. These formulae are valid for any electric potentials. The results relatively well agree with those of Monte Carlo simulations. The first Townsend ionization coefficient differs substantially from that resulting from the Townsend formula. The velocity distribution function spatially varies and contains several groups of fast electrons. Using the detour factor the angular scattering can be included in the calculations.