AXUV探测器标定及受辐照响应衰减研究

Calibration and Study on Irradiated Response Attenuation for AXUV Detector

在EAST和HT-7装置上,具有宽能谱响应的AXUV光电二极管探测器主要用于辐射功率的绝对测量。探测器在经历多轮等离子体放电中的累积辐照效应后,观察到其表面发生变化。为了解探测器响应衰减程度,设计了相对标定实验,分别采用标准可见光光源和软X射线管作为标定光源,对EAST和HT-7实验中经历过不同放电次数的5个探测器进行了标定。标定结果表明,AXUV探测器在经历了EAST上约25 000次的等离子体放电累积辐照后,其在软X射线能段的响应下降约15%。而探测器在可见光能段的辐照损伤效应主要表现为同一个探测器不同通道之间对可见光响应的不一致性加剧。结合探测器在等离子体放电辐射场中的几何参数,对探测器受到的累积辐照剂量进行了估算。

The relative calibration method of AXUV photodiodes used on the nuclear fusion Tokamak EAST and HT-7was given.These photodiodes were used for absolute radiated power measurement.The changes of the detector surface were usually observed after one experiment campaign.Five sensors suffered different plasma discharge irradiations were compared by relative calibration.The X-ray tube and standard light source were chosen as the calibration source.The results show that the detector response can decrease 15% after 25 000 discharge irradiation accumulations.The response changes between channels in one photodiode array were observed.The cumulative irradiation doses were evaluated according to the geometry parameter of the detector in radiation field.