Silicon Diode Fast Neutron Dosimeter, Phase I, Evaluation of Response Versus Starting Material

摘要

The report presents the results obtained from an investigation of the effects of (n- or p-type) silicon, resistivity, and method of crystal fabrication (pulled or float-zone) on the response of silicon-diode fast-neutron dosimeters. The high-level lifetime, the reverse-recovery lifetime, and the current-voltage characteristic were measured for diodes fabricated from each type of starting material, and these parameters were then followed as the diodes were exposed to various neutron fluences. Preliminary results of isochronal annealing experiments and the effects of maintaining the diodes at low temperatures during irradiation are also presented. It was expected that the high-level damage constant, derived from the high-level lifetime, would be independent of the resistivity of the starting material, and this was demonstrated experimentally. Annealing results suggest that at least seven levels are involved in the degradation of lifetime by fast neutrons, and studies of devices irradiated at 77K and 273K revealed an increased amount of observed damage. (Author)