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

In the conduct of this research effort, neutron activated Sn sources and standard radioactive sources were used to simulate the gamma energy spectrum of a nuclear weapon pit. A converging hole collimator was designed, constructed, and mated with an HPGe Double Sided Strip Detector. A MATLAB image processing code was developed to produce a grayscale image of the sources. A variety of source configurations was examined to demonstrate the system's ability to obtain proper spatial distribution information for a multinuclide gamma emitting source. By replacing the converging hole collimator with a second detector array (as in a Compton camera) to improve detector efficiency, HPGe strip detectors may be used for the intended application of identifying the presence of a "spoof" weapon pit consisting of multiple nuclide sources meant to mimic a real weapon pit.