Microstructural evolution in Fe-Cr-Ni alloy irradiated by controlled neutron

It is necessary to establish the fission-fusion correlation to evaluate radiation effects in fusion environment from the results of fission reactor irradiation. In the present work, nucleation and growth of interstitial loop were investigated by the controlled fission and fusion neutron irradiation. The density of loops formed in the both irradiations increased linearly with the fluence, and no change in the loop size distribution was observed. The present study showed that the loops were nucleated directly by the defect processes in a cascade zone but not by the reaction among the free defects in the matrix. If the rate of loop formation is directly proportional to primary knock-on atoms (PKA) energy of neutrons, the threshold energy is 80 keV and rate of loop formation is 0.05. (author)