Radiation Production From Stagnating Compact Toroids Employing a NonequilibriumRadiation Diffusion Model

摘要

The stagnation of a high Z, high velocity compact toroidal plasma against astationary object has been shown computationally to be an efficient radiation source. To obtain a better understanding of the stagnation process and the influence of various prestagnation properties on radiation production, the 2 1/2 dimensional radiation magnetohydrodynamic code, MACH2, was used to simulate the stagnation physics. To perform these calculations, a flux-limited non-equilibrium radiation diffusion model was incorporated into the MACH2 code. In this model the radiation field evolves separately from the material components of the fluid and is described by a Plankian distribution at the radiation temperature, TR. This introduced a dynamic equation for the radiation field and modifications to both the momentum and electron energy equations. A flux-limited version of the radiative conductivity was formulated to extend this model into the optically thin regime. Detailed benchmarking of the radiation diffusion and electron-radiation coupling using a set of radiation MHD test problems was conducted. (AN).