对NPN双极晶体管进行了低剂量率下不同偏置条件的电离辐射实验。结果表明,不同偏置条件下的低剂量率辐射损伤具有明显差异。基-射结反向偏置时,其过剩基极电流最大,电流增益衰减最为显著。而基-射结正向偏置时,过剩基极电流和电流增益衰减都最小。讨论了出现这种结果的内在机制。 The experiment of ionizing radiation with different bias conditions at low dose rate was carried out on NPN bipolar transistor. The results showed that there were significant differences in radiation damage at low dose rates under different bias conditions. When the base-emitter junction is reverse biased, the excess base current is the largest and the current gain attenuation is the most significant. When the base-emitter junction is forward biased, the excess base current and current gain attenuation are both minimized. Discuss the underlying mechanism for this result.