ION-BEAM ANALYSIS OF MGAL2O4 SPINEL IRRADIATED WITH FAST-NEUTRONS TO 50-250 DPA

Non-destructive ion beam analysis techniques have been employed to exa mine the radiation damage in MgAl2O4 spinel single crystals irradiated with fast neutrons at 400 and 750 degrees C to high fluences (equal t o or greater than 25x10(22) n/cm(2), E(n)>O.1 MeV). Rutherford backsca ttering and ion channeling measurements using 1-4 MeV He-ion beams rev ealed that the radiation damage saturated after irradiation at 400 deg rees C to 50 displacements per atom. The energy dependence of dechanne ling indicated the dominant extended defects present in the highly irr adiated spinel are in the form of dislocations. Channeling angular sca ns of particle induced X-ray emission further suggested that neutron i rradiation tends to randomize cation distribution for Me(2+) and Al3cations on the lattice sites, These results are compared to the micros tructure observations of Kinoshita et al, and the neutron scattering r esults of Sickafus et al.