Pellet ablation in Tokamak reactors

Abstract

We implemented a rotational cloud model for the simulation of pellet ablation in a Tokamak reactor. We have shown that the ablation rate in the rotational cloud model converges quickly to a steady state value independent of the plasma warmup time. In contrast, the ablation rate in the non-rotating cloud model converges slowly to a value that depends upon the warmup time. We have also extended the neutral gas shielding (NGS) model for Maxwellian plasma electrons. A tumbling pellet model has been implemented. We have also compared the simulation results using a MUSCL scheme and a Discontinuous Galerkin (DG) scheme with a specialized nonuniform grid suited to the pellet problem in one space dimension, and developed a localized Discontinuous Galerkin method to solve the pellet ablation problem. One and two dimensional results are presented.