7 irradiation damage of photo -diodes and photo - transistors has been studied. The irradiation doses were 104

105 and 106Gy（Si）

respectively. The experimental results showed that the light current Ip

current amplification factor β and response time to photo -devices were all decreased while dark current Id increased and junction capacitance C unchanged basically. After 72 h of annealing at 180 ℃

the electro - parameters of the photo -devices stored for 180 days were not well restored

which indicated that 7 irradiation would induce not only instant but also partially permanent damage.