SBIR/STTR Award attributes
C49-18b-271098Novel neutron detectors with =300 µm spatial resolution and gamma rejection = 10-6 are needed to enable efficient measurement of small single crystals for diffraction and diffuse scattering measurements, which are essential for advancing a variety of scientific research from biomedical drug discovery, materials innovation to clean energy technology. Currently used GS20 scintillator works but the single crystal diffractometer cannot achieve the desired resolution due to low brightness of GS20. We will address the current limitations by using an advanced scintillator, made in a large area, microcolumnar film format that heretofore was not possible to grow because of the extreme hygroscopicity of the material, which emits a relatively low number of photons/MeV gamma but has a reported yield of ~100,000 photons per thermal neutron interaction, a factor ~20 higher yield than current GS20 glass. The high thermal neutron efficiency of this material implies that only ~1.0 mm of scintillator thickness is needed to absorb about 60% of 1Å neutrons. The Phase I & II research successfully demonstrated the feasibility of fabricating large-area structured scintillators, developed techniques to hermetically seal these extremely hygroscopic films, and through process optimizations, demonstrated a light yield of ~135,000 photons per thermal neutron interaction, which is the highest brightness amongst neutron scintillators. This was accomplished by meticulously adjusting the dopant concentration in the films and correlating the brightness to the dopant content. With such high brightness, new Anger cameras can reach sub-150 µm spatial resolution. In the Phase IIA, protocols to produce large-area thick films will be optimized for consistency in performance and improved yields. This will require modifications to the deposition system enable uniform large area film fabrication. Films up to 2.5 mm in thickness with optimized composition will be fabricated and packaged using the latest advances in polymer and inorganic conformal coatings to create pinhole free moisture barriers. The efficacy of the scintillator will be demonstrated at Oak Ridge National Laboratory, with the goal of realizing sub-150 µm spatial resolution, ~1×10-7 gamma rejection and 80% neutron absorption efficiency. RMD’s scintillator/detector will be an excellent choice for neutron detectors for any facility that runs neutron experiments. For example, at Oak Ridge National Laboratory, large-area detectors at the Spallation Neutron Source are used for neutron scattering experiments and in materials research for a variety of applications. There are 45 neutron research centers located around the world that will want to take advantage of our technology.
