Cooperative Radiation Effects Simulation Program

Progress for the period 1 May 1975 to 31 March 1976 includes a continuation of studies on the stability of gamma prime, Ni3Al, precipitates in nickel under ion bombardment. Another study characterizes the microstructure and swelling in an Fe-25Ni-15Cr alloy bombarded with 2.8-MeV Ni(+) ions as part of the national alloy development program effort to establish correlations between various charge-particle irradiations and neutron damage. Irradiation creep studies on pure nickel were conducted at temperatures of 224C and stresses of 170 to 345 MPa. Transport code calculations on the deposition of energy into a target bombarded by heavy ions are continued for the case of antimony on germanium. A study of homogeneous void nucleation theory showed that it was necessary to use a time-dependent theory to analyze charged-particle irradiation experiments. A form of this theory was developed which could be practically applied to directly calculate void-size distributions which qualitatively correlated with experimental results. Ion bombardment techniques, data analysis, and interpretation of the ion bombardment results and the results of neutron irradiation of Mo are described. See also report dated Aug 75, AD-A015 085.