Design and modeling of the hybrid portable gamma camera system

The combination of a mechanically-collimated camera with an electronically-collimated camera offers an industrial gamma-ray imaging system with good angular resolution and efficiency over a broad energy range: 50 keV to 3 MeV. The design and performance modeling of the Hybrid Portable Gamma Camera, currently being built, is described here. The optimization of the Anger-logic first detector module in terms of spatial and energy resolution results in 6 mm spatial resolution and 7.5% FWRM (statistical contribution only) energy resolution for a 140 keV incident energy on the 100×100×10 mm³ NaI(Tl) first detector crystal. Analytical calculations of angular resolution components and efficiency for the Hybrid Portable Gamma Camera are compared to Monte Carlo calculations of the same quantities. The expected angular resolution performance for on-axis point sources, a central scattering angle of 30° and a detector separation distance of 35 cm ranges from 3-5° FWHM over the sensitive energy range. Intrinsic efficiency results over the same energy range are also presented