Two kinds of operational amplifiers LM118J-8 and OP07
and a reference device 7F3140
were irradiated with 60Coγrays and their radiation responses were measured in situ simultaneously.The results show that the output voltages of OP07 amplifier changed obviously at 100 Gy(Si)
while LMll8J-8’s did not change obviously until 900 Gy(Si).It is shown that LMll8J-8 amplifier has better radiation tolerance than 0P07
and that their different radiation tolerances result from different configurations and technologies of circuits.The invalidity and degradation of LMll8J-8 and 0P07 amplifier can be attributed to theγ-radiation-induced interface states.