The use of silicon transitors as damage monitors in reactor neutron metrology

Measurements of neutron induced damage to silicon bipolar transistors using Cf-252 sources have been performed in order to establish a technique for use in fast neutron metrology. It is found that the change in inverse d.c. current gain before and after irradiation is a linear function of the fast neutron fluence up to 1014 h(1 MeV)/cm2. The problem of partial annealing of damage during exposure was overcome by carrying out controlled annealing cycles after retrieval of transistors from the exposure and prior to gain measurements. Also annealing measurements have been performed at temperatures up to 1800C. (Auth.)