Silicon Diode Fast-Neutron Dosimeter. Phase IV. Determination of the Energy Dependence of the Damage Constant

摘要

Monoenergetic neutron irradiations of 50-mil-base-width silicon diodes were performed to determine the neutron energy dependence of the electrical parameters of the p-i-n diodes. The T(p,n)He3, D(d,n)He3 and T(d,n)He4 reactions and the Ohio State University 5.5-MeV Van de Graaff were used to produce neutrons having energies from 0.36 to 22.5 MeV. The diodes were fabricated from high lifetime, 600 ohm-cm, p-type material. The lifetime of the material in the base of the diode was typically 60 microsec. The energy dependence of the neutron bombardment degradation of two diode parameters was investigated. The parameters studied were damage coefficient for storage time and forward-voltage sensitivity at constant current. Neutron fluences in the range of 10 to the 9th to 2 x 10 to the 10th power n/sq cm were employed for the irradiations. The results showed that the neutron energy dependence of the two parameters were identical and varied approximately as the square root of neutron energy for neutron energies from 0.36 to 4.77 MeV. For neutron energies above 4.77 MeV the experimental results do not follow a systematic trend. (Author)