Preparation of a Standard Technique for Determination of Neutron Equivalence for Bulk Damage in Silicon

This report defines how a neutron energy (1 MeV) equivalence should be calculated and the limitations of its utility. The differences in the l-MeV equivalence obtained by using Messenger´s expression for the damage curve is examined. An experiment was performed to verify the adequacy and utility of using l-MeV equivalence units to compare different neutron spectra. It is shown that for fission spectra close to a bare reactor that l-MeV equivalence provides a slight improvement in the correlation of data taken from devices irradiated at different reactors. However, this improvement in correlation did not extend to devices irradiated with 14 MeV neutrons. The devices irradiated in this experiment showed a fission/fusion fluence ratio for equal damage of about 1.7 rather than the expected value of 2.5.