A Prototype of Large Area and Highly Sensitive Coded Aperture γ Camera

Gamma cameras play an important role in radioactive source loss, smuggling and large-scale nuclear radiation security sites. This paper proposed a prototype of large area and highly sensitive coded aperture γ camera based on the probe of Hamamatsu BHP6601 SPECT. The detector with large area of 510 × 390 mm
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and high intrinsic spatial resolution of 3.55 mm effectively improve the sensitivity of the system. The coded mask designed by tectonic analysis has a rank of 23 and centered mosaicked by 2×2, which is a total size of 1020×780 mm
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. The focal length of the system is 441mm. The system has a high detection capability for long-range or low-activity sources: it can accurately locate 1mCi
¹³⁷
Cs point source for 1s at 18m; and it only takes 2s to reconstruct the position of 30μci
¹³⁷
Cs which is 4m away from the system. Among present products, it has a large non-artifact field of view (NAFOV) of 57.32° and a small spatial Angle resolution of 3.92° in X direction. Besides, it is cost effective and high detection efficiency. There is potential for the system in rapid detection of radioactive sources in large range.