Effects of heat treatment on trapping and release of tritium from He pre-irradiated tungsten

The effects of heating on retention of tritium implanted into tungsten pre-irradiated with helium have been examined by β-ray-induced X-ray spectrometry (BIXS), which gives information about changes in the amount and depth profile of tritium retained on/in materials. Tritium implantation and isochronal heating of the helium pre-irradiated and un-irradiated tungsten samples were repeated as a series of experiments, and changes in the X-ray spectra were measured in each heating cycle. Quite different decreasing behavior between Ar(Kα) and W(Mα) X-ray intensities for both samples was observed in the heating process, and it was seen that the majority of tritium implanted into the helium pre-irradiation sample was trapped by the radiation defects rather than in helium bubbles.