The Suitability of Copper/Lithium Alloys for Application as Wall Material in Tokamaks

Abstract In Cu/Li alloys of low lithium content, the lithium component segregates to the surface, forming a protective overlayer. When applied as wall material in a tokamak, the sputtering of the high- Z copper component can be reduced by a considerable amount. To learn about the behavior of the Cu/Li binary system under particle bombardment, detailed investigations have been carried out during the last few years. The experiments show that wall temperatures above 400 ° C are necessary to achieve a distinct lithium coating effect. The protective layer cannot be maintained permanently under low-energy light-ion irradiation and needs a periodic conditioning procedure. However, a numerical extrapolation of measured layer lifetimes particle flux densities relevant to fusion reactors shows that it is worthwhile to consider a test of Cu/Li alloys as wall material in a tokamak.