The influence of rhenium addition on the distribution of vacancy-type defects in tungsten

Abstract

Abstract To investigate the influence of transmutation rhenium on the irradiation-induced defects in tungsten, H+ and He+ irradiation of 50 keV with a fixed fluence of 1\xa0×\xa01016 atoms·cm−2 were conducted on WxRe (x =0, 3, 5 and 25 wt.%) alloys, respectively. Doppler Broadening Spectroscopy and Coincidence Doppler Broadening Spectroscopy both based on slow positron beam were employed in the current work to characterize the depth distribution and the chemical surroundings of the irradiation-induced defects. The results showed that under 723K irradiation, Re addition suppressed the accumulation of vacancy-type defects compared with pure W. This suppression was enhanced by increasing Re content in W. An obvious Re-related peak from (7-28)\xa0×\xa010−3 m0c was observed in CDB spectra of well-annealed W-Re alloys. The irradiation effect led to the height deviation of Re-related peak. The decrease of the Re-related peak could be attributed to the formation of irradiation-induced defects in irradiated samples, and the reduction of positron annihilation fraction with core electrons of Re.