Low temperature irradiation effect on iron and iron-alloys

Fundamental studies of radiation-induced defects in iron and iron-chromium alloy, molybdenum have been performed by using a positron annihilation lifetime measurement, tensile test and computer analysis. Difference between fission neutron and fusion neutron irradiation on iron and molybdenum was observed and concluded to be due to gas atoms (He, H) produced by nuclear transmutation. Vacancy migration stages for various iron alloys and other metals were obtained and contributed to the analysis of void swelling in high temperature heavy irradiation. A typical example of radiation-induced softening (the decrease of yield stress) was observed in iron single crystal specimens and detailed analysis of the interaction between a screw dislocation and a self-intersititial atoms was presented. (author)