Multispectral Gamma Detector for Explosives Analysis

In order to effectively manage hazardous environments, one requires a detailed knowledge of those materials that pose a threat to valued assets. Through both detector characterization and system modeling, we demonstrated the feasibility of using a gamma-ray camera based on inorganic scintillators as a means to rapidly image high explosives and other organic materials at intermediate to long ranges, when they are impinged upon by a high-flux neutron stream. In particular, we developed a 2,304 element prototype imager based on high brightness pixelated scintillators coupled to arrayed silicon photomultipliers. The custom high-speed data acquisition system and associated data-handling and display software confirmed the analytical prediction that a plane array of CsI(Tl) or LYSO(Ce) is a feasible method of rapidly imaging explosives at intermediate ranges. What remains is to increase the detection and imaging efficiency so that one can maximize the stand-off range at which high-probability detection is elicited. During the Phase II research, we will build the high-efficiency prototype and demonstrate its effectiveness in the field.