A review of particle-solid processes pertinent to modelling plasma-wall interactions is presented, and sets of recommended data are given. Analytic formulas are used where possible; otherwise, data are presented in the form of tables and graphs. The incident particles considered are e−, H, D, T, He, C, O, and selfions. The materials include the metals aluminum, beryllium, copper, molybdenum, stainless steel, titanium, and tungsten and the nonmetals carbon and TiC. The processes covered are light ion reflection, hydrogen and helium trapping and detrapping, desorption, evaporation, sputtering, chemical effects in sputtering, blistering caused by implantation of helium and hydrogen, secondary electron emission by electrons and particles, and arcing.

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Sputtering yields for different ions and materials at low ion energies have a similar energy dependence. Due to this similarity, yield data can be characterized by a normalized energy function and two parameters for each ion target combination. One of these parameters is the threshold energy. An energy scaling can be based on this parameter. The other parameter is a multiplication factor. Both parameters depend mainly on the ion and target mass M1 and M2 and on the surface binding energy EB. An analytic expression for the normalized functions and both the parameters is given. This empirical relation also allows an estimate of unknown sputtering data, if M1, M2, and EB are noted. A physical interpretation of the empirical relation is given for the case M1≪M2, as in this case special collision processes which dominate the sputtering can be identified.

The total erosion yields of several types of graphites have been measured during high ion flux exposure in the PISCES plasma facility. Hydrogen and deuterium plasmas have been used to bombard Poco, ATJ, pyrolytic, and C-SiC-coated graphites, and a ‘4-D’ C-C composite weave. Erosion experiments with ion fluxes of up to 2 × 1018 cm−2 · s−1, at ion energies of 50 to 200 eV and sample temperatures of 50 to 950°C, are reported. In the absence of redeposition, the erosion rates of all the graphites tested is essentially the same. The C-C composite weave material showed equal or lower erosion yields compared to the other graphites over the range of temperatures tested. The maximum total carbon erosion yield at 600°C increased by a factor of two for 50 eV ion bombardment and by a factor of five for 200 eV ion bombardment, compared to the reference values found for room temperature samples. At temperatures above 800°C, the chemical erosion is suppressed and the erosion yield reaches values expected for physical sputtering. A direct comparison with two ion beam experiments with an ion flux three orders of magnitude lower than used in PISCES showed total erosion rates within a factor of two, indicating that chemical sputtering is not significantly suppressed by high ion fluxes. The results show that the chemical sputtering of graphite limiters or divertor plates in tokamaks will vary by a factor of only two to three over a limiter temperature range of 0 to 800°C if the incident ion energy is less than 100 eV as is observed in tokamak experiments. The net erosion is also strongly reduced by reionization in the plasma and redeposition of both hydrocarbons and physically sputtered carbon.

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