Damage function for carbon at neutron energies up to 15 MeV

Highly-oriented-pyrolytic-graphite samples were irradiated in three different neutron sources with average energies of 1.5, 5.5, and 15 MeV, respectively. The resulting changes in the basal-plane elastic shear moduli of these samples show that the relative damage rate is substantially higher at the higher neutron energies than is predicted by existing models. The results of these experiments have been used to generate a new relative damage function which will allow better projections of graphite radiation behavior in fusion reactors based on data obtained by irradiations in fission reactors. (orig.)