Polarisation in the Temperature Equilibration of Anisotropic Plasmas

Abstract

AbstractThe polarisation effect on the isotropisation of a magnetized bi-Maxwellian plasma is investigated in the weak coupling approximation. Based on the Rostoker collision operator, which reduces in the magnetic field free limit to the Balescu-Lenard operator, the equipartition frequency v is evaluated numerically for B→0 and analytically for B→∞, respectively. This frequency, depending nonlinearly on ε and B, describes the approach to thermodynamic equilibrium of the anisotropy parameter ε = T⊥/T‖ via dε/dt - (1 - ε) ν(ε, B). It is found that in both limits dynamical screening makes a negligible contribution to the relaxation process. For finite B a simplified, yet unexploited expression for ν(ε, B) is presented, which invokes three new functions