TRAPPING OF DEUTERIUM IN BORON AND TITANIUM-MODIFIED GRAPHITES BEFOREAND AFTER CARBON ION IRRADIATION

Nuclear reaction analysis was used to investigate the retention of deu terium (D) at radiation damage in new graphites USB-15, PGI, RG-Ti-91, RG-Ti-91 with 0.5 wt%B made in Russia and in POCO AXF-5Q graphite. Sa mples were irradiated with C+ ions to produce damage up to doses of ap proximately 10 displacements per atom (dpa), and then soaked in deuter ium gas at 1473 K. The concentration of D in the damaged region increa sed with damage and saturated for damage levels above about 1 dpa. At saturation the smallest D concentration was found in USB-15 (approxima tely 60 appm), and the largest D concentration was found in RG-Ti-91 ( approximately 1500 appm). Based on microstructural investigations done by TEM, an attempt was made to relate differences in concentrations o f retained D to variations in radiation-induced trap concentration and to kinetic limitations for D atom access to traps available. The effe ct of boron on D trapping in graphite was also examined.