Simulation Study of Shocked Particle Velocity Distributions in a HANE DisturbedPlasma

摘要

A two dimensional, hybrid particle in cell simulation code is used to study thevelocity distributions of a plasma disturbed by a collisionless shock wave generated by a high altitude nuclear explosion. Knowledge of the velocity distributions is crucial in understanding plasma instabilities that thermalize the disturbed plasma and produce the ion deposition spectrum. Variation in the deposition spectrum can cause orders of magnitude differences in IR radiation and ionization and strongly affect systems. The simulations indicate that the relevant anisotropic velocity distributions are shell like rather than bimaxwellian. Since almost all theoretical analysis of thermalizing plasma instabilities have been based on bimaxwellian distributions, this research motivates a reexamination of thermalizing instabilities using velocity distributions that are more physically realistic.