Radiation Processes in Plasmas

TLDR

The study examines arbitrary test current sources in an infinite homogeneous Vlasov plasma, showing that various radiation problems can be addressed by selecting appropriate current sources. The authors compute the work of test sources on the plasma to obtain energy emission into transverse and longitudinal waves, derive bremsstrahlung spectra from time‑varying dipole moments of shielded electron‑ion encounters, model wave scattering and coupling from density‑fluctuation‑generated currents, and equate emission and absorption rates to determine steady‑state wave energy densities.

Abstract

The problem of arbitrary test current sources embedded in an infinite spatially homogeneous Vlasov plasma is considered. By computing the rate at which the test sources do work on the plasma, the energy emission into transverse and longitudinal waves is obtained. A variety of radiation problems can be handled by appropriate choice of the current sources. Use of the time varying dipole moment due to encounters between shielded electrons and ions leads to expressions for the bremsstrahlung spectra. If the currents are produced by the interaction of waves with density fluctuations, the scattering and coupling of waves is obtained. By equating the rate of emission of longitudinal or transverse waves to their rate of absorption, expressions for the steady-state energy densities of such waves are obtained.