Measurements on transistors subjected to nuclear radiation

Selected types of low-frequency transistors were exposed to Co^∞gamma radiation and to a reactor flux of neutrons. Forward and reverse characteristic curves were photographed as the irradiation progressed. Reverse currents of the emitter and collector junctions were recorded. These data are used to distinguish changes of surface recombination velocity from those associated with the minority carrier lifetime. The character of damage due to gamma and to neutron irradiation is thus identified. Effects upon transistors exposed just to the reactor environment are compared with those due to successive exposure to Co^∞gammas and to reactor neutrons.