Quantification of the sticking coefficient of hydrocarbons on fusion relevant carbon and tungsten surfaces

摘要

We report on the quantification of the sticking coefficient of deuterated hydrocarbons CD2+ andCD3+ on fusion relevant carbon fiber composite (CFC) and plasma-sprayed tungsten (PSW)surfaces in the collision energy range from about 0 up to 100 eV. The samples were cut fromASDEX Upgrade tiles and collided by an energy selected ion beam. The resulting hydrocarbonlayers on the target surfaces are ex-situ analysed by Nuclear Reaction Analysis (NRA) viaD(3He,p)4He at 800 kV and 2.5 MeV, respectively. The sticking coefficient S for deuterium liesbetween S=0.1 to S=0.5 and is collision energy dependent, decreasing with increasing energy. Alsosecondary ion mass spectra of charged particles are recorded after ion-surface collisions.