成像板伽马图像测量研究

研究了成像板辐射图像测量的基本原理及其物理机制，并将其应用于伽马图像测量。建立了MS，SR和TR三种类型成像板数值模拟模型，分别使用MCNPX程序和基于Geant4开发的NPE程序计算了三种成像板对不同能量伽马射线的能量沉积，计算结果表明:SR和MS成像板比TR成像板能量沉积在低能部分大3~5倍，高能部分大7~9倍。实验测量了MS成像板灵敏度随铜膜厚度的变化关系，测量结果与理论计算结果有较好的一致性。理论与实验结果表明:成像板伽马图像测量的空间分辨力优于50 m。

Imaging plates applied to gamma-ray image measurement

Basic principles and physical mechanism of image measurement by using imaging plates(IPs) are studied in this paper, and fundamental problems about applications of the IPs in gamma-ray image measurement are also analyzed. Monte Carlo models of imaging plates in common use are built, involving three types of IPs, i.e. MS, SR, TR. And the energy deposition of gamma rays of different energies in the IPs are calculated through the MCNPX code and the NPE code based on a Geant4 platform. As a result, the energy deposition of SR-type and MS-type IPs is 3-5 times larger than that of TR-type IPs in the low energy part, and 7-9 times larger in the high energy part. The theoretical and experimental results of the relation between gamma-ray sensitivity of MS-type IPs and copper foil thickness agree well with each other. The spatial resolution of IPs in gamma-ray imaging is better than 50 μm.