Formation condition of fiberform nanostructured tungsten by helium plasma exposure

摘要

Tungsten samples were irradiated by high density helium plasma in the divertor plasma simulator NAGDIS-II to investigate the formation condition of the fiberform nanostructured tungsten. Experimental result indicates that the surface temperature threshold exists around 1000 K. When the surface temperature is above 1130 K, when the incident ion energy is 50 eV, the fiberform nanostructure thickens with the increase of the sample temperature. Three samples manufactured by different procedure (ultra fine grained tungsten, ITER-reference tungsten grade and powder metallurgy tungsten) were exposed to helium plasma, and the nanostructure was formed in all the samples