A portable gamma camera for radiation monitoring

A compact gamma camera capable of imaging high energy gamma rays (up to 2 MeV) is currently being developed for nuclear industrial applications. This camera uses a three inch square position sensitive photomultiplier tube (PSPMT) [Hamamatsu, R-2487-05] coupled to a NaI(Tl) scintillator. The incoming gamma ray direction is determined by a segmented collimator. The camera exhibits energy resolutions of 17% FWHM at 122 keV and 12% FWHM at 662 keV. With the collimator design used, an angular resolution at the source plane of 6/spl deg/ FWHM was measured for 412 keV. Images have been obtained using gamma ray sources up to 1 MeV using this system. The image reconstruction technique used is presented in detail. Corrections for the non-uniformities across the face of the PSPMT are implemented to improve the spatial and spectral information content in the final image.<
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