Development of the Real-Time Portable Neutron Spectroscope (NSPECT) for Detection and Identification of Special Nuclear Materials*

We describe the development of the Neutron Spectroscope (NSPECT) prototype detector capable of real-time neutron source location and identification. Real-time detection and identification fills an important gap in locating Special Nuclear Materials (SNM). NSPECT is suitable for locating SNM by detecting fission neutrons and reconstructing images of their source. NSPECT is an instrument with imaging and energy measurement capabilities that is sensitive to neutrons in the 1-20 MeV range. The detection principle is based upon multiple elastic neutron-proton scatterings in an organic scintillator. The instrument utilizes two detector panel layers. By measuring the recoil proton and scattered neutron energies, the direction and energy spectrum of the incident neutrons can be determined and discrete sources identified. Event reconstruction gives NSPECT the capability to provide an image of the source of interest. The design of NSPECT is a low power, low mass, rugged instrument, suitable for field deployment. Its modular design allows the user to combine multiple units for increased sensitivity.