Numerical simulation of strong evaporation and condensation for plasma-facing materials

There are no data available for the vapor pressure and the evaporation and condensation rates of plasma-facing materials (PFMs), such as carbon, tungsten and beryllium, in the range of very high temperatures (above 10 000 K). Therefore, we have developed two computer codes to evaluate the evaporation and condensation rates of PFMs. One of these codes is a finite difference code for solving the Boltzmann-Krook-Welander (BKW) equations, that assume the material vapor phase to be a fluid; the other is a direct simulation Monte Carlo (DSMC) code. Some numerical results for the vapor pressure, temperature and density distributions, and the evaporation and condensation rates near the surface of the PFMs at high temperature, are compared with the results from the BKW and DSMC codes, and also are compared with the existing experimental correlations.