A method for the inhibition of carbon-film formation in hidden areas of the divertor for tritium inventory control in tokamak

Carbon fibre composites (CFCs) planned to be used in the International Thermonuclear Experimental Reactor (ITER) divertor can be eroded due to hydrogen species from the plasma and the resulting hydrocarbons can be redeposited in other locations. Tritium retention in redeposited materials is the major concern due to the limits imposed for safety reasons by the nuclear licensing authorities. The scavenging effect has already been proposed to decrease the carbon redeposited materials using nitrogen as a scavenger. To date, only fairly limited data are available on the use of NH3 as a scavenger. In this brief communication, the possibility of performing the inhibition of carbon-film formation using NH3 was examined. (Some figures in this article are in colour only in the electronic version)