Novel Semiconductor-based Tileable Fast Neutron Imager

Neutron radiography (NR) has become an important complement to traditional X-ray radiography (XR) because of its ability to highlight defects in the low-density components, even when they are obscured by high-density components. Thus, energetic fill and voids, gaskets and any low-density components including fuses can be imaged better using NR than using traditional XR, enabling thorough inspections of ammunition, armaments, and other products for quality, safety, and lethality. Portable high-flux neutron sources are now available, but detectors that can fully utilize the potential of these sources do not exist. The problem is exacerbated for high-energy (fast) NR with portable sources primarily producing fast neutrons. We have previously demonstrated the feasibility of high spatial resolution, minute timescale fast NR using a scintillator-based flat panel detector (FPD). However, scintillator-based FPDs have limited sensitivity, fixed imaging areas, and lack the flexibility to customize the imaging area. We, therefore, propose to develop a tileable detector with high spatial resolution, high-sensitivity, and high signal-to-noise ratio for fast NR. Extensive Geant4 modeling will be performed to design the high-resolution, high-efficiency fast neutron imager. Various semiconductor prototype structures will be fabricated, and their performance evaluated under fast neutron exposures to demonstrate the feasibility of our approach.