Subroutines for some plasma surface interaction processes: physical sputtering, chemical erosion, radiation enhanced sublimation, backscattering and thermal evaporation

A suite of FORTRAN subroutines/functions to generate data using empirical formulas for physical sputtering of monoatomic targets for any elemental incident ion (atom), chemical erosion of graphite, Radiation Enhanced Sublimation (RES) of graphite, the number and energy backscattering coefficients for any elemental incident ion (atom) on a compound target and thermal evaporation of graphite is presented. Since chemical erosion, RES and thermal evaporation depend on the surface temperature of graphite, a subroutine implementing the 1-D heat diffusion equation to determine the temperature of any plasmafacing graphite surface is implemented. As an example to illustrate the use of these subroutines/functions, a simple model for the erosion of a plasma-facing surface, consisting of a simple collisionless sheath model, a 1-dimensional steady state heat diffusion model and 0-dimensional steady state particle balance at the target is developed and a sample listing of the program is presented.