Radiation trapping simulations using the propagator function method: complete and partial frequency redistribution

An integral method for solving the problem of imprisonment of resonance radiation based on propagator functions is further developed. Earlier work was restricted to plane parallel and spherical geometries, to a Lorentz lineshape, and to the approximation of complete frequency redistribution. This work extends the method to cylindrical geometry, to a Voigt lineshape, and to include the effects of partial frequency redistribution. The method is ideal for calculating both the time-dependent and the steady-state densities of resonance atoms which result from an arbitrary production rate per unit volume. An emission spectrum is also generated in calculations involving partial frequency redistribution. The propagator function method is at least 50 times faster than the Monte Carlo method. The greater speed of the propagator function method makes it well suited to fully self-consistent kinetic simulations of glow discharge plasmas.