Power Optimizing Petabyte Disk System

65689 For an increasing number of human diseases, smaller animals such as mice and rats can serve as effective models. Accordingly, high-resolution radionuclide imaging, such as positron emission tomography (PET), of small animals can contribute unique information. However, clinical PET scanners used for human imaging are bulky and expensive, and do not have adequate spatial resolution for small animal studies. Dedicated, low cost instruments are required for these small animal studies, with higher spatial resolution than currently achieved with clinical PET scanners. This project will utilize position sensitive avalanche photodiodes (PSAPDs) coupled to LSO arrays as PET sensors for small animal PET imaging. During Phase I, PSAPDs were fabricated using two designs and evaluated. PET sensors and modules were fabricated by coupling LSO crystals and arrays to PSAPDs. Studies of energy resolution, timing resolution, flood histogram, and depth of interaction were conducted, and the feasibility of the proposed approach was demonstrated. Phase II will optimize the PSAPD design, fabricate such devices, and use them to build PET modules. After an extensive evaluation of the modules, a prototype PET scanner will be built and tested. Commercial Applications and Other Benefits as described by the awardee: In addition to medical imaging, the new detectors should be applicable to nuclear physics studies, non-destructive evaluation, geological exploration, industrial computer tomography imaging, X-ray instrumentation, space physics, and materials analysis.