Rates of Total and Local Radiative Energy Losses in Nonequilibrium Plasmas

Abstract

Radiative losses are calculated for some combinations of an infinite slab, infinite cylindrical, finite cylindrical, or spherical enclosure of plasma and a constant, linear, parabolic, trigonometric, or periodic distribution of Planck’s function caused by non-uniformity in electron temperature. The local loss rate on an axis or a center becomes higher as non-uniformity in Planck’s function increases. The rate increases with the increasing distance from the axis or the center in the case of constant Planck’s function. On the contrary, for symmetric functions with monotonic decrease, it becomes lower with the increasing distance and negative in the region near enclosure surfaces.
The results obtained here are available for the estimation of radiative energy loss from nonequilibrium plasmas in magnetohydrodynamic devices. Especially, the result for periodic distribution of Planck’s functions is useful for an analysis of plasmas with fluctuations in electron temperature such as ionization instabilities.