Nuclear Material Accountability Applications of a Continuous Energy and Direction Gamma Ray Detector

The Idaho National Laboratory has recently developed a detector system based on the principle of a Wilson cloud chamber that gives the original energy and direction to a gamma ray source. This detector has continuous energy resolution and the direction to the source can be resolved to desired fidelity. Furthermore, the detector has low power requirements, is durable, operates in widely varying environments, and is relatively inexpensive to produce. This detector is expected, however, to require significant measurement time. Advantageously, because of the use of compressed air, the detector is expected to scale to very large sizes with a linear increase in cost. The proof of principle detector has an active region of 100,000 cm3. Applications of this detector are described in the context of nuclear material monitoring.