10~100 keV能区硬X光探测器精密校准及应用

Precise Calibration and Application of Hard X-Ray Detector in Energy Range of 10--100 keV

在惯性约束聚变实验研究中,硬X光能谱的定量诊断设备滤波荧光谱仪的核心探测元件为硬X光闪烁探测器。鉴于此,建立一种基于半导体硬X光二极管的硬X光探测器能量灵敏度校准方法,其具有快速简便的优点,量值溯源不依赖放射源强度,校准不确定度为7%。首先,利用该方法分别在硬X光机和上海同步辐射光源上实现对碘化钠和氟化钡闪烁探测器在不同能量灵敏度范围的能量灵敏度校准。其次,使用蒙特卡罗模拟程序Geant4计算两种类型探测器的理论灵敏度曲线,并与校准实验结果进行比较分析,将校准数据外推到整个能量范围(10~100 keV)。最后,将该方法应用到真空隔离片能量透过率的精密校准,低灵敏BaF_(2)闪烁探测器的校准结果可应用于高亮度硬X光源实验的研究。

In the experimental study of inertial confinement fusion, the core detection element of the filter fluorescence spectrometer in quantitative diagnostic equipment for hard X-ray spectroscopy is the hard X-ray scintillation detector. In view of this, a method for calibrating the energy sensitivity of hard X-ray detectors based on semiconductor hard X-ray diodes is established, which has the advantages of fast and simple. The traceability of the quantity does not depend on the intensity of the radioactive source, and the calibration uncertainty is 7%. First, the proposed method is used to calibrate the energy sensitivity of sodium iodide and barium fluoride scintillation detectors in different energy sensitivity ranges on hard X-ray machine and Shanghai synchrotron radiation light source, respectively. Second, the theoretical sensitivity curves of the two types of detectors are calculated by using the Monte Carlo simulation program Geant4, and compared with the calibration experimental results, the calibration datasets are extrapolated to the whole energy range(10--100 keV). Finally, the proposed method can be applied to the precise calibration of energy transmittance of vacuum isolator, and the calibration results of low sensitive BaFscintillation detector can be applied to the experimental study of high brightness hard X-ray sources.