Encoding methods matching the 16 × 16 pixel CZT detector of a coded aperture gamma camera

• 作者: Jin-Chao Ma Pin Gong Rui Zhang Xiao-Bin Tang Xiao-Lei Shen
• 来源期刊: 核技术（英文版）
• 年，卷（期）: 2020,（9）
• 所属期刊栏目: NUCLEAR ELECTRONICS AND INSTRUMENTATION
• 页码范围: 82-89
• 页数: 8页
• 语种: 英文

摘要

With the advancements in nuclear energy, methods that can accurately obtain the spatial information of radioactive sources have become essential for nuclear energy safety. Coded aperture imaging technology is widely used because it provides two-dimensional distri-bution information of radioactive sources. The coded array is a major component of a coded aperture gamma camera, and it affects the key performance parameters of the camera. Currently, commonly used coded arrays such as uniformly redundant arrays (URAs) and modified uni-formly redundant arrays (MURAs) have prime numbers of rows or columns and may lead to wastage of detector pixels. A 16 × 16 coded array was designed on the basis of an existing 16 × 16 multi-pixel position-sensitive cad-mium zinc telluride detector. The digital signal-to-noise (SNR) ratio of the point spread function at the center of the array is 25.67. Furthermore, Monte Carlo camera models and experimental devices based on rank-13 MURA and rank-16 URA have been constructed. With the same angular resolution, the field size of view under rank-16 URA is 1.53 times that of under rank-13 MURA. Simula-tions (Am-241, Co-57, Ir-192, Cs-137) and experiments (Co-57) are conducted to compare the imaging perfor-mance between rank-16 URA and rank-13 MURA. The contrast-to-noise ratio of the reconstructed image of the rank-16 array is great and only slightly lower than that of rank-13 MURA. However, as the photon energy increases, the gap becomes almost negligible.