Laboratory and computer simulations of super-Alfvenic shocks in a weakly ionized medium

摘要

High Mach number shocks have been studied experimentally at the Kurchatov Institute in 2000 with the PF3 Plasma Focus [N. V. Filippov , Phys. Lett. A 211, 168 (1996)]. The main goal of these especially designed laboratory experiments was to provide data against which to test current numerical models, in order to better understand the interaction of a high-velocity plasma jet with a partially ionized gas in a strong transversal magnetic field. Observed magnetic field compression, plasma density profile evolution, and shock slowing down, are well reproduced by a two-dimensional hybrid code HAWAI2D [B. Lembege and F. Simonet, Phys. Plasmas 8, 3967 (2001)] with Monte Carlo collisions. Some of the code initial conditions are directly obtained from the numerous diagnostics installed in the experimental chamber. Others are derived from jet velocity and background density measurements, making use of a simplified model of jet propagation from the pinch. Ion-neutral collisions play a central role in the shock dynamics, as demonstrated in the simulations. (C) 2003 American Institute of Physics. [References: 33]