Helium release measurements and diffusion coefficient calculations of helium in a neutron-irradiated α-SiC have been carried out in the temperature range of 750 1,260°C. The powder was obtained from SiC ceramics containing B4C, of which 10B concentration was 4.2×1016atom/mg. Neutron irradiation was conducted up to a fluence of 2.8×1024n/m2 (E>0.1 MeV) -300°C. The diffusion coefficients were calculated for the temperature region of 750-1,060°C with time range of 0-10 min. The diffusion coefficient of helium for SiC containing B4C was D (cm2/s)=1.38×1010exp[—0.91±0.07 (eV/atom)/kT]. Dissociative and interstitial diffusion mechanisms were supposed. Diffusion coefficients were reduced above -1,160°C probably due to accelerated migration of vacancies.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics
- Nuclear Energy and Engineering