Material erosion at the vessel walls of future fusion devices

For a next-step fusion device the erosion at the vessel walls during normal operation caused by the bombardment with different species from the plasma is estimated. The wall fluxes are calculated for a given ‘burning’ plasma with the computer code B2-EIRENE. With the known sputtering yields the erosion rates for vessel walls made out of Be, C, Fe, Mo or W, are calculated. The erosion by ions is found to be of the same order of magnitude as the erosion by energetic neutrals. The erosion has minima around the area of gas feed and maxima close by and at the bottom near the baffles of the divertor. The calculated total erosion is of the order of 1021 to 1022 atom/s for low Z materials, and a factor 10–20 lower for high Z materials, such as W, resulting in about 5 kg per full-day of operation or 1 t/y.