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

A new algorithm is presented for the explicit calculation of the electromagnetic fields in 2D simulation plasmas. This paper describes a multi-fluid model for the simulation of laser plasma interaction. Our description includes a simple two-electron fluid model and the background ions in a laser target, as coupled fluid components moving relative to a fixed Eulerian mesh. The electrons become a perfect gas obeying the non relativistic Maxwell–Boltzmann distribution. Braginskiiʹs expression is used. The magnetic field equation is integrated in time by the Lax–Wendroff modified scheme, a method that is known to be stable as long as the Courant–Friedrichs–Lewy condition is satisfied. The first approximation step (1)Bm+1/2=〈Bm〉+(〈vm〉×Bm)Δt/2 is followed by the full step (2)Bm+1=Bm+(vm+1/2×Bm+1/2)Δt. With the explicit treatment of V×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 (Bz), which leads to a 5-diagonal, sparse matrix that can be solved by both ADI an TDMA.