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 car bon, tungsten and beryllium, in the range of very high temperatures (a bove 10 000 K). Therefore, we have developed two computer codes to eva luate the evaporation and condensation rates of PFMs. One of these cod es is a finite difference code for solving the Boltzmann-Krook-Welande r (BKW) equations, that assume the material vapor phase to be a fluid; the other is a direct simulation Monte Carlo (DSMC) code. Some numeri cal results for the vapor pressure, temperature and density distributi ons, and the evaporation and condensation rates near the surface of th e PFMs at high temperature, are compared with the results from the BKW and DSMC codes, and also are compared with the existing experimental correlations.