Experimental study on sequential reactions in fusion reactor materials by D-T neutron irradiation

Hori, Junichi; Sato, Satoshi; Yamauchi, Michinori*; Ochiai, Kentaro; Nishitani, Takeo

D-T neutron irradiation experiments have been performed with F82H and ODS ferritic steels and the effective cross sections for Co productions in those materials via the sequential reactions were measured. The effective cross sections for F82H and ODS ferritic steels were about 1.5 times larger than that for iron. The distributions of effective cross sections were measured for 6 materials (iron, copper, vanadium, titanium, tungsten and lead) and F82H. The sequential reaction rates in the region close to hydrogen compound became over 20 times larger than that in material itself. In the case of F82H, the increase ratio was about 50. It was indicated that the activity for the sequential reaction product Co will reach to 3-10 of that for primary neutron reaction product Mn aound the surface of a cooling pipe in a fusion reactor. The effective cross sections were estimated by using (n,xp), (p,n) reaction cross sections, proton emission spectra, proton stopping power in the material. The estimated values were compared with experimental results.