The neutron irradiation effect on commercial three-terminal regulators

The neutron irradiation effect on Two types of commercial three-terminal regulators (CJ79L05011 and CJ7905011) worked under different loads was studied by experiment. And then the relationship between the output voltage of the regulators and the fast neutron flux was observed. It was predicted that the decrease of current gain of transistors resulting from the neutron radiation damage was the main cause for the failure of three-terminal regulators from the simplify model of the regulator. The relationship between the output voltage of the regulator and the current gain of transistors in the internal of the regulator was also deduced from the simplify model. At the same time, the relationship was calculated under the help of the software of PSPICE. The simulated results were in good agreements with experimental data. It has been proved that the analysis for the radiation damage in regulators by neutrons was right. (authors)