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模拟构建了双层康普顿相机,利用康普顿散射原理,获取γ光子在两层探测器发生散射前后沉积的能量和位置信息,通过一定算法进行图像重建,获得放射源位置信息。该相机具有灵敏度高、体积小、应用范围广等优点。通过蒙特卡罗方法模拟了具有双层条状结构位置灵敏探测器(散射探测器、吸收探测器)组成的康普顿相机,其两层探测器分别由Si和Ge材料构成。利用反投影图像重建算法实现了放射源图像重建,当单点源与探测器距离为40 mm时,成像的效率为0.38%,位置分辨率达到8.0 mm,角分辨率达到3°。对于不同位置和不同个数点源的情况下,检验了反投影重建算法在康普顿相机放射源空间重建中的效果。
A two-layer Compton camera was constructed by simulating the Compton scattering principle. The energy and position information of the γ-photon scattering before and after the scattering of two detectors was obtained. The image was reconstructed by a certain algorithm to obtain the position information of the radiation source. The camera has high sensitivity, small size, wide range of applications and so on. A Compton camera with two-layer strip structure position sensitive detector (scattering detector, absorption detector) is simulated by Monte Carlo method. The two-layer detector consists of Si and Ge materials respectively. The reconstruction of the radioactive source image was achieved by the back projection image reconstruction algorithm. The imaging efficiency was 0.38%, the position resolution was 8.0 mm and the angular resolution was 3 ° when the distance between the single point source and the detector was 40 mm. For different locations and different number of point sources, the effect of the back-projection reconstruction algorithm on the spatial reconstruction of the Compton camera source space was tested.