Synergistic effects by simultaneous bombardment of tungsten with hydrogen and carbon

The simultaneous bombardment of a W surface by hydrogen isotopes and carbon impurities leads to synergistic effects with significantly different plasma–wall interaction properties compared to the ones of pure hydrogen or pure carbon bombardment. Simultaneous impact of carbon and hydrogen ions has been realised by irradiation of W targets with CH3+ radicals produced by a high current ion source. For comparison, the same experiment was also carried out with C+ ions. The measured evolution of the target weight as a function of irradiation fluence and the final amount of deposited carbon are compared to a simple model of erosion–deposition balance. This allows one to derive the dependence of the carbon sputtering yield on both the impacting ion species and the target temperature.