Development of the Particle-Mesh, Material-Interaction Particle-In-Cell Code Package (PEMMICAN) for the Simulation of Plasma Facing Component Wall Effects*

The vapor shielding effect occurs when a plasma impinges on a surface, depositing energy and inducing vaporization, leading to interaction with the impinging plasma. This plasma-vapor interaction results in an overall reduction of the energy deposited at the material surface. The Particle-Mesh, Material Interaction Particle in Cell code package (PEMMICAN) was developed to simulate vapor generation as a result of plasma energy deposition on tungsten, iron, carbon, and lithium targets. PEMMICAN is also capable of simulating plasma-vapor interaction between a tungsten vapor and a deuterium-tritium plasma via electron impact ionization and radiative recombination. The development and verification of PEMMICAN is presented in this paper. The underlying model implemented in PEMMICAN is described and relevant theory is discussed. Verification tests are presented, including measurement of simulated electron and ion gyrofrequencies and Larmor radii, electrostatic repulsion, E⨯B drift, grad-B drift, spatial and temporal stability analysis, vaporization mechanics, and electron impact ionization and recombination mechanics. Good agreement between the underlying model and simulation results were found. Notably, near exact agreement was found between simulated electron and ion Larmor radii in a strong magnetic field and the corresponding analytical value. Concluding thoughts, current efforts, and future work are discussed.