建立了XCounter Flite X1型光子计数探测器的响应函数模型。利用X射线荧光作为射线源, 通过蒙特卡罗方法, 模拟了入射能谱与探测器材料中的能量沉积能谱。响应函数包括高斯函数与经验型的修正函数, 修正函数由直线段构成, 通过最小二乘的方法来确定其中的参数, 探测器像素不一致性的校正包括阈值校正与响应函数的校正。把经过校正的模型结果与实验结果对比并计算平均误差, 得到在各能量段下误差都小于2.5%的结果, 利用该响应函数进行能谱恢复与材料分解, 两者具有比较理想的结果, 充分说明了该校正方法的有效性与准确性。

A response function model for the XCounter Flite X1 photon counting detector was built. Using X-ray fluorescence as ray-source, the incident spectrum and the deposited spectrum were simulated by Monte Carlo method. Gaussian model and phenomenological model were used in the response function, while the parameters were determined by the least square method correspondingly. The inconsistency correction of the detector consisted of the threshold correction and the function correction. So that the error between the simulation result and experiment data was less than 2.5% in each energy bin. The spectral restoration and material decomposition result with the response function get much closer to the ground-truth, which shows the effectiveness and accuracy of the proposed method.