ABSORPTION AND EMISSION COEFFICIENTS OF NONEQUILIBRIUM PLASMAS

In non-equilibrium plasma spectroscopy it may happen to have to deal w ith ensembles of particles, whose velocity distribution is not the equ ilibrium (i.e. Maxwell) one. Consequently, the shape-profile-of the re levant emission or absorption coefficient is different from the profil e (Gauss or Voigt) that corresponds to the equilibrium velocity distri bution function. The computation of the emission and absorption coeffi cients in the case of an arbitrary velocity distribution can be painst aking and, above all, risky from the numerical point of view. In this paper, we present an easy way to perform the above computations. As a consequence, the treatment of the corresponding inverse problem also b ecomes easy: the reconstruction of a velocity distribution function, o nce the values of the corresponding emission (or absorption) coefficie nt are known for all the directions and frequencies.