Diffuse X-ray scattering studies on defect clusters in Ni irradiated by high-energy ions and electrons

Pure Ni was irradiated with high-energy (150MeV Phosphorus) ions up to dose s of 5.3 x 10(13), 1.6 x 10(14) and 4.1 x 10(14) ions/cm(2) and with 2MeV e lectrons up to 3 x 10(18) e(-)/cm(2). The resulting defect structures were studied at roam temperature using diffuse X-ray scattering (DXS) methods. T he size distribution of dislocation loops was analyzed by fitting the theor etical diffuse X-my scattering intensities of the dislocation loops to the experimental ones. The number density of vacancy loops increased linearly w ith dose whereas their sizes did not increase. This implies that a vacancy- loop nas formed by single cascade. On the other hand, the size of interstit ial loops for the case of high-energy ion-irradiation was smalls than that for electron-irradiation, indicating the annihilation of free interstitials contributing to the formation of large interstitial-loops for high-energy ion-irradiation.