Photoelectric response of ICMOS on total dose irradiation

An irradiation experiment for an image-intensified sensor(Intensified Complemetary Metaloxide Semiconductor,ICMOS)was performed with a 60Co-γray source to evaluate its weak-light-detecting ability under the total dose irradiation.When the total dose of irradiation reached the predetermined point,the change of photoelectric response capability of the sensor was measured quantitatively by an off line method.The experiment results show that as the total dose of irradiation increases,the photoelectric response capability decreases rapidly.When the total dose of irradiation reaches 60krad(Si),the photoelectric response capability is reduced to 6%.The causes of decline of the photoelectric response capability were analyzed according to the components of the image-intensified sensor and empirical equations of the decline of the photoelectric response capability were also derived.The experiments demonstrate that the decline of the photoelectric response capability is compensated by improving the voltage gain of the image-intensified sensor.When the total dose of irradiation reaches 25krad(Si),the photoelectric response capability still maintains 100%by improving the voltage gain of the image-intensified sensor of 0.23 V meanwhile maintaining agood weak-light-detecting ability.These findings showthat the image-intensified sensor is able to withstand 25krad(Si)of the total dose irradiation.