An Inexpensive, Material-Specific, Gamma-Ray Detector

"The objective of this proposed research is to develop a gamma-ray detector capable of detecting specific atomic species (e.g. N and O) of composite materials such as explosives, nuclear materials and drugs. The detector will detect nuclear resonancefluorescence (NFR) characteristic lines from specific atoms without using time-consuming pulse-height analysis. The resonance detectors will be sufficiently inexpensive to permit their incorporation into either linear or large-area arrays for detectionand imaging. The research will proceed by the design, fabrication, and testing of a prototype detector capable of detecting a specific atomic species (e.g. nitrogen) from composite materials. A major goal will be to achieve a large area, sensitive detectorcapable of rapid identification. The detector will be made of materials that can be scaled to increase the device¿¿s collection aperture and sensitivity. The potential for successful development of the detector is high because of the simplicity of thedesign and prior research. A manufacturer of accelerators has expressed interest in the detectors for integration into existing ¿x-radiographic imaging systems. The proposed device is capable of integration with existing gamma-radiographic systems, whichare currently being used for imaging large containers, trucks, and cargo. Sensitive, large aperture detectors can be airborne and, thus, can be useful for identification of materials emitting