Year
2018
Abstract
The combination of gamma-ray spectroscopy and high-resolution imaging is useful for characterizing materials of interest in a number of applications including waste management, safeguards, and security. Although directional spectroscopy has been demonstrated by others in the research and defense arenas, there are additional technical challenges associated with designing a compact device with comparable performance. We have developed a highly portable gamma-ray imaging spectrometer with integrated coded aperture mask for high-quality gamma-ray imaging at low energies. The sensitive detector plane consists of four tightly-packed 10-mm-thick pixelated CdZnTe crystals that achieve about 1% FWHM energy resolution at 662 keV. These 3D-position-sensitive detectors measure the energy-dependent shadow of a rank-19 MURA coded aperture mask that automatically rotates between mask and antimask configurations to reject unmodulated background. Here we discuss the technical challenges associated with extracting high-quality spectroscopic and directional information from these measured data in the context of safeguards.