Explicit electromagnetic algorithm for 2D using a multi-fluid model in laser-produced plasmas

A new algorithm is presented for the explicit calculation of the electromag netic fields in 2D simulation plasmas. This paper describes a multi-fluid m odel for the simulation of laser plasma interaction. Our description includ es a simple two-electron fluid model and the background ions in a laser tar get, as coupled fluid components moving relative to a fixed Eulerian mesh. The electrons become a perfect gas obeying the non relativistic Maxwell-Bol tzmann distribution. Braginskii's expression is used. The magnetic field equation is integrated in time by the Lax-Wendroff modif ied scheme, a method that is known to be stable as long as the Courant-Frie drichs-Lewy condition is satisfied. The first approximation step Bm+1/2 = [B-m] + ([upsilon(m)] X B-m)Delta t/2 is followed by the full step Bm+1 = B-m + (upsilon(m+1/2) X Bm+1/2)Delta t. With the explicit treatment of V X B in the fluid equation used, the matrix equation solved for the magnetic field reduces, from a 7-point coupling to a 5-point one to its nearest neighbors, in the direction z (B-z), which le ads to a 5-diagonal, sparse matrix that can be solved by both ADI an TDMA. (C) 2000 Elsevier Science B.V. All rights reserved.