Special Nuclear Material Imaging Using a High Purity Germanium Double Sided Strip Detector

The purpose of this research is to investigate the feasibility of using a High Purity Germanium Double Sided Strip Detector (HPGeDSSD) to image Special Nuclear Material (SNM) for use in the field of nuclear nonproliferation. SNM shape can be determined by using a gamma ray imaging system that is capable of imaging either Pu-239 or U-235. The detector used for this research is a liquid-nitrogen cooled germanium detector with five charge collection strips on both faces. The strips on the two faces are orthogonal to each other, creating a five by five array of data collection pixels. When the detector is coupled to a parallel hole collimator, an imaging system is achieved. The system is capable of imaging individual or multiple photon energies. The capability of the imaging system to produce images of simulated Pu-239 was demonstrated. The analyses of the images allowed distributed sources to be distinguished from point sources, which was the primary goal for developing this technology