MODELING ION INTERPENETRATION, STAGNATION, AND THERMALIZATION IN COLLIDING PLASMAS

Ion interpenetration, stagnation, and energization processes are studi ed in colliding laser-produced plasma configurations relevant to Tride nt [R. G. Watt, Rev. Sci. Instrum. 64, 1770 (1993)] experiments using four different numerical methods: one-dimensional Monte Carlo and Lagr angian multifluid codes, and one- and two-dimensional hybrid (particle ions, fluid electrons) and single-fluid Lagrangian codes. Results fro m the four methodologies are compared for plasmas generated with gold and deuterated polyethylene (CD2) targets. Overall, the various codes give similar results concerning the initial expansion of the plasmas a nd their collisional interaction, the degree of stagnation, stagnation time, and amount of ion thermalization for gold targets, while multis pecies techniques indicate a much softer stagnation for CD2 plasmas th an the single-fluid model. Variations in the results of the calculatio ns due to somewhat different initializations and parameters, as well a s to different physics in the codes, are discussed. (C) 1996 American Institute of Physics.