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

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