FOKKER-PLANCK MODELING OF ELECTRON-TRANSPORT IN LASER-PRODUCED PLASMAS

Fokker-Planck (FP) codes have become useful tools for modeling nonloca l heat-transport phenomena in laser-produced plasmas. Several possible simplifications to the FP equation as well as different numerical tec hniques available for its solution are investigated. The most robust a nd efficient approach is found to involve the diffusive approximation of the FP equation and the alternating-direction-implicit method of so lution. The SPARK FP code, which has been developed along these princi ples, is described in detail. It incorporates fluid ions and solves fo r transport on either a two-dimensional Eulerian grid or a one-dimensi onal Lagrangian grid. Sample simulation results are presented, togethe r with a discussion of possible improvements to the code.