Strongly-Perturbed Non-Equilibrium Gas Physics Model for the Paraxial Diode Transport Cell.

摘要

Intense short-pulse charged-particle beams those with tens or hundreds of kA/cm2 and beam risetimes less than 100 ns can disturb the background gas so severely that not only are diatomic molecules ionized, but molecules may be dissociated and the product atoms themselves multiply ionized. Such beam-background systems are generally far from temperature and species equilibrium. The plasma conductivity (sigma), which is determined by the degree of ionization and the species temperatures, strongly influences the beam behavior through the plasma return current. Thus, simultaneously and self-consistently solving for both and the beam propagation is essential for a correct description of the system behavior. A plasma physics model with advanced gas chemistry has been developed and incorporated into the simulation code LSP to help meet this objective.