Comparison of MultiGroup Radiative Diffusion and Tabular CollisionalRadiativeEquilibrium Transport Methodologies
Abstract
When solving for the ionization dynamics and radiation transport in a multidimensional Zpinch simulation of a laboratory plasma, it is computationally prohibitive to selfconsistently couple the ionization dynamics to a solution of the equation of radiative transfer. In order to make such an effort computationally feasible there are several methodologies that can be employed to approximate the solution. In this study we examine two such models: 1) the multigroup LTE diffusion algorithm â which is adequate at large density and/or large optical depths, and 2) the tabular collisional radiative equilibrium (TCRE) model, which is based on CRE and probabilityofescape methods for which the nonlocality of the problem is reduced to transporting a single line per ionization stage. In particular we compare radiation and ionization dynamics results from these two models with results calculated by a CRE model that is selfconsistently coupled to a probabilityofescape radiation transport model. This model represents our benchmark for the solution to the full transport problem. Comparisons are made for numerous static density and temperature profiles that characterize the implosion phase of a laboratory Zpinch to determine the range of plasma conditions for which the LTE diffusion and/or TCRE approximations are reasonable.
 Publication:

APS Division of Plasma Physics Meeting Abstracts
 Pub Date:
 October 2003
 Bibcode:
 2003APS..DPPLP1140T