多类图像传感器模组电离辐射损伤对比研究

Comparative Study on Ionizing Radiation Damage of Different Types of Image Sensor Modules

为选择能用于γ射线辐照环境且最具有加固潜力的图像传感器模组,对比分析了7类传感器模组辐照前后实时采集明、暗图像的参数,研究了不同类型的模拟图像传感器模组及数字图像传感器模组的抗辐射性能,并讨论了辐射损伤机理。实验结果表明:γ射线对图像传感器模组的损伤及干扰程度与模组类型、图像传感器制作工艺、辐照剂量率及总剂量相关;剂量率造成的干扰与剂量率并非呈单纯的线性关系;镜头透镜的透光率随累积剂量的增大而下降;入射γ射线对采集画面质量的干扰与环境光线强度相关,较弱的真实信号更易被入射光子引入的噪声淹没。以上结果提示,入射γ射线对图像传感器的损伤及干扰主要是由各像素单元内暗电流以及正向脉冲颗粒噪声引起的。经实验分析,采用互补金属氧化物半导体(CMOS)工艺的数字摄像机更适用于γ射线辐射环境中的实时监测,但仍需通过加固手段提高其在辐射环境中工作的可靠性和使用寿命。

In order to select the type of image sensor module which is suitable forγ-ray irradiation environment and has the most potential ability for radiation hardening,seven types of image sensor modules were studied by analyzing the parameters of bright and dark images before and after irradiation.The radiation resistance of different types of analog and digital image sensor modules was studied,and the radiation damage mecha-nism was also discussed.The experimental results show that the damage and interference degree of the image sensor module is related to the module type,the process of the image sensor,the irradiation dose rate and the total dose.The radiation damage does not show simple linear relationship with the dose rate.The light transmittance of the camera lens decreases with the increase of the total dose.The interference by the incidentγ-ray on the quality of the collected pictures is related to the intensity of the ambient light,and the weaker real signals are more likely to be flooded by noises induced by the incidentγ-ray.As a conclusion,the primary damage and interference of the incidentγ-ray on the image sensor are caused by the dark current and positive pulse noise in each pixel.According to the experimental analysis,digital module using CMOS technology is more suitable for online monitoring in radiation environment,but it is still necessary to improve the reliability and service life by means of radiation hardening.