Electron kinetics in radio-frequency magnetic fields of inductive plasma sources

Abstract

The influence of the radio-frequency (RF) electromagnetic field on electron dynamics in analysed both analytically and numerically, with an emphasis on the magnetic field, B. The magnetic field can be important for inductive plasma sources or other plasmas in which the rapid spatial decay of the electric field arising from a skin effect produces a large B via Faraday's law. Principal consequences of including B are a change in the velocity component heated, a reduction in the electron density in the RF-field region, both instantaneous and time-averaged, and a reduction in the magnitude of the heating by the inductive fields, both at the level of individual particles and averaged over an isotropic distribution. We calculate analytical expressions for the instantaneous and averaged density reduction and the single-particle heating rates, and find good agreement with results from a multi-particle orbit code. We also give numerical results for the heating rate averaged over a Maxwellian distribution. The results are contrasted with those obtained previously when B was neglected.