Low Temperature Irradiation of Iron, Zirconium and Copper by 10 to 16 MeV Protons

Abstract

<p>Scattering and radiation damage parameters are analytically evaluated for 14 MeV neutrons and 10-17 MeV protons on Fe, Ni, Cu, Zr, Nb and Au. Damage energies are computed for the interactions using both elastic and non-elastic data. The theoretical results show that proton encounters deposit a damage-energy greater by factor of two than that calculated for mono-energetic 14-MeV neutron events.</p> <p>To examine the theoretical results, electrical resistivity measurements are undertaken for Fe, Zr and Cu irradiated at 12 to 17.5K with 10 to 16 MeV protons. The resistivity change is measured as a function of dose. In addition, post-irradiation isochronal annealing is carried out in-situ using a closed-cycle helium-cooled cryostat.</p> <p>Values of the resistivity damage rate are determined from the experimental plots of Δρᵢ versus Φt, and compared with the values of dΔρᵢ/dΦt estimated from the theoretical damage-energy results. Also, the observed stage-I recovery is analysed in terms of the corresponding recovery reported for electron and fast-neutron irradiations. The data analysis also includes a discussion of the relation between the present 16-MeV proton data and published data estimated from a fusion-reactor spectrum.</p> <p>The results presented in this thesis indicate that 16 MeV protons approximate the anticipated damage due to a fusion-reactor spectrum. It is also shown that protons create a damage structure similar to a superposition of the damage structures generated by electrons and fast-neutrons. The sample state of imperfection is shown to influence the induced damage-state in proton irradiation.</p>