硅漂移探测器探测效率标定研究

Research on detection efficiency calibration of silicon drift detectors

单能X射线标定装置是基于布拉格衍射原理产生单能X射线的装置,能量连续可调的单能X射线可以为探测器提供能量可选的详细标定实验。使用蒙特卡洛计算软件对两个不同型号的硅漂移探测器的探测效率进行模拟计算,得到3~50 keV能量段的探测效率,在单能X射线标定装置上完成了硅漂移探测器探测效率的标定实验,得到实验测量的探测效率曲线,并与模拟效率曲线对比。其中,PNDetector公司的MLC型硅漂移探测器的实验结果与理论计算结果的误差最大值为4.23%@15 keV,KETEX公司的BEV 133型硅漂移探测器的实验结果与理论计算结果的最大误差为-6.88%@12 keV。结果表明,在7~16 keV能量段,两个探测器的实验标定结果与理论计算结果相符,在8 keV左右,实际探测效率大于90%。研究成果验证了使用基于布拉格晶体衍射原理的单能X射线用于探测器标定的优越性,为国产化X射线探测器提供可靠的性能研究与测试平台。

Monochromatic X-rays calibration facility is a device that generates monochromatic X-rays based on Bragg diffraction.The continuous adjustable monochromatic X-rays can provide detailed calibration experiments with optional energy for a detector.Monte Carlo calculation software is used to simulate the detection efficiency of two different types of silicon drift detectors,and the detection efficiency of the 3~50 keV energy band is obtained.The calibration experiment of the detection efficiency of the SDDs is completed on the monochromatic X-rays calibration facility,and the detection efficiency measured by the experiment is obtained and compared with the simulation efficiency.Moreover,the maximum error between the experimental results and the theoretical calculation results of MLC SDD is 4.23%@15keV,and the maximum error between the experimental results and the theoretical calculation results of BEV 133 SDD is-6.88%@12keV.The results show that the experimental calibration of the two detectors are consistent with the theoretical calculation results in the energy band of 7~16 keV,and the real detection efficiency is greater than 90%at 8 keV.The research results verify the superiority of using Bragg diffraction-based monochromatic X-rays for detector calibration,and also provide a reliable performance research and testing platform for domestic X-ray detectors.