Chemical behavior of hydrogen isotopes into boronized film in LHD

In D-T fusion experimental devices, it is expected that oxygen and carbon could be contained as impurities in boron film produced by boronization. The chemical behavior of hydrogen isotopes implanted into boron films prepared in LHD at NIFS was studied by comparing the LHD sample with the P-CVD samples prepared at Shizuoka University. The LHD sample formed B–D–B, B–D, B–C–D and B–O–D bonds by D2+ implantation. B–C–D and B–O–D bonds were mainly formed by the reaction of B–C and B–O bond with implanted D2+, and C–C bond and free oxygen were mainly formed the hydrocarbon and water during D2+ implantation. It was suggested that the total D retention of the LHD sample was slightly larger than that of only the carbon- or oxygen-containing boron sample prepared by P-CVD. This could be largely affected to the amount of C–C bond and free oxygen which formed the hydrocarbon and water.