A theoretical model for the He effect upon the radiation swelling of SiC was suggested. This model was based upon considering the kinetic growth of dislocation loops in the matrix, taking into account the effect of an internal electric field formed near to dislocation loops had upon the diffusion processes of charged point defects. The trapping of He atoms by vacancies resulted in an enhanced growth rate of dislocation loops and finally a swelling increase. The theoretical results for radiation swelling were compared with existing experimental data. It was shown that He atoms increased the radiation swelling of SiC; especially at high temperatures.

Effect of Helium on Dislocation Loop Formation and Radiation Swelling in SiC. A.I.Ryazanov, A.V.Klaptsov, A.Kohyama, Y.Katoh, H.Kishimoto: Journal of Nuclear Materials, 2004, 329-333, 486-91