Compact API system using a semiconductor alpha detector

The proliferation of nuclear weapons presents unparalleled danger. Critical to preventing the spread of such weapons of mass destruction is the detection and characterization of both the production and movement of special nuclear materials. Neutron interrogation techniques, including Associated Particle Imaging (API), are valuable tools in the nonproliferation effort, but the limited capability of portable neutron systems tightly constrains their application. Advancements in the versatility, performance and portability of neutron generators, and API generators in particular, are needed. Adelphi is leveraging recent advances in its neutron generator technology along with low-cost semiconductor alpha detectors developed at the Stanford Linear Accelerator Center to produce a revolutionary, hand-portable API neutron imaging system. With the advent of its solid-state microwave driven electron-cyclotron-resonance ion source, Adelphi is able to reduce the size and weight of its API neutron generators to less than 8 liters and 30 pounds, requiring only 200 watts of input power or less. Furthermore, taking advantage of the precision tuning of the solid-state microwave drive, the neutron output can be adjusted over two orders of magnitude, allowing the generator to be used for both single particle counting elemental analysis, which requires a low intensity, and projection imaging, which requires a high intensity. SLAC’s semiconductor detectors provide a rugged, very low-cost solution to provide the spatial resolution necessary for an API system. Subcomponents and capabilities of the system will be demonstrated in Phase I, including the output variability, neutron production target, and alpha detector, resulting in the design of the full system to be built in Phase II