光纤耦合GAGG_Ce型X射线探测器高分辨成像

Fiber-Coupled GAGG_Ce X-ray Detector for High-Resolution Imaging

闪烁屏信号串扰是影响X射线探测器空间分辨率的主要因素,基于点扩散函数理论对光纤耦合GAGG_Ce单晶闪烁屏型CCD/CMOS探测器的空间分辨率进行了研究。利用蒙特卡罗程序EGSnrc和光学仿真软件Zemax分别对GAGG_Ce单晶闪烁屏射线串扰和荧光串扰进行了仿真。仿真结果表明,对于低能X射线辐射成像,荧光串扰是影响探测器空间分辨率的最主要因素。此外,研究了通过降低光纤面板数值孔径以抑制荧光串扰的方法,得到了光纤面板数值孔径与探测器空间分辨率和X射线转换因子间的关系,并通过自制CCD探测器测试验证了仿真结果的正确性。

The crosstalk of scintillation screen signals is the main factor that affects the spatial resolution of X-ray detectors. The spatial resolution of fiber-coupled GAGG_Ce single crystal scintillation screen CCD/CMOS detector is studied based on the point spread function theory. The ray crosstalk of GAGG_Ce single crystal scintillation screen and fluorescence crosstalk are simulated by Monte Carlo program EGSnrc and optical simulation software Zemax respectively. The simulation results show that fluorescence crosstalk is the most important factor affecting the spatial resolution of the detector for low-energy X-ray radiation imaging. In addition, the method of suppressing fluorescence crosstalk by reducing the numerical aperture of optical fiber panel is studied, and the relationship among numerical aperture of optical fiber panel, detector spatial resolution and X-ray conversion factor is obtained. The correctness of the simulation results is verified by the self-made CCD detector test.