Calderón Y, Chmeissani M, Kolstein M, De Lorenzo G
Instituto de Física de Altas Energías (IFAE), Edificio Cn, Universidad Autónoma de Barcelona (UAB), E-08193 Bellaterra (Barcelona), Spain.
J Instrum. 2014 Jun;9(6). doi: 10.1088/1748-0221/9/06/C06003.
A proposed Compton camera prototype based on pixelated CdTe is simulated and evaluated in order to establish its feasibility and expected performance in real laboratory tests. The system is based on module units containing a 2×4 array of square CdTe detectors of 10×10 mm area and 2 mm thickness. The detectors are pixelated and stacked forming a 3D detector with voxel sizes of 2 × 1 × 2 mm. The camera performance is simulated with Geant4-based Architecture for Medicine-Oriented Simulations(GAMOS) and the Origin Ensemble(OE) algorithm is used for the image reconstruction. The simulation shows that the camera can operate with up to 10 Bq source activities with equal efficiency and is completely saturated at 10 Bq. The efficiency of the system is evaluated using a simulated point source phantom in the center of the Field-of-View (FOV) achieving an intrinsic efficiency of 0.4 counts per second per kilobecquerel. The spatial resolution measured from the point spread function (PSF) shows a FWHM of 1.5 mm along the direction perpendicular to the scatterer, making it possible to distinguish two points at 3 mm separation with a peak-to-valley ratio of 8.
为了确定基于像素化碲化镉的康普顿相机原型在实际实验室测试中的可行性和预期性能，对其进行了模拟和评估。该系统基于模块单元，每个模块单元包含一个由面积为10×10 mm、厚度为2 mm的方形碲化镉探测器组成的2×4阵列。探测器被像素化并堆叠在一起，形成一个体素大小为2×1×2 mm的三维探测器。使用基于Geant4的面向医学模拟架构（GAMOS）对相机性能进行模拟，并使用原点集成（OE）算法进行图像重建。模拟结果表明，该相机在源活度高达10 Bq时仍能以相同效率运行，在10 Bq时完全饱和。使用位于视野（FOV）中心的模拟点源体模评估系统效率，本征效率达到每秒每千贝克勒尔0.4计数。从点扩展函数（PSF）测量得到的空间分辨率显示，在垂直于散射体的方向上半高宽为1.5 mm，这使得能够分辨间距为3 mm的两个点，峰谷比为8。
