Effect of deuterium retention upon sputtering yield of tungsten by deuterons

Sputtering yields of tungsten from tungsten containing deuterium (D2) and tungsten containing carbon (C) atoms bombarded by deuterium and carbon atoms are calculated with a Monte Carlo code ACAT. The ACAT results have shown that the tungsten sputtering yields are changed by carbon retention in tungsten. The tungsten sputtering yield by deuterium bombardment around the sputtering threshold for pure tungsten have been enlarged by two mechanisms; one is the reduction in sputtering threshold due to smaller surface binding energy, the other is the enhanced development of collision cascade. As the carbon bombarding energy exceeds 200-300 eV, the sputtering yields for tungsten retaining deuterium and carbon become smaller due to the reduction in density of tungsten target atoms.