NEXT Neutron Detector Modules based on High Density SiPM Arrays and Novel Organic Glass Scintillator

To maximize its research potential The Facility for Rare Isotope Beams FRIB) requires a neutron tracking array NEXT) with both efficiency and energy resolution at least three times better than the current VANDLE, while also providing excellent gamma-ray rejection over a wide neutron energy range. Unfortunately, the only economically viable NEXT design to date, using EJ276 scintillator and H12700 position sensitive PMTs, does not achieve the timing resolution to achieve the energy resolution in bars that are long enough to also meet the efficiency specification and provide a good neutron-gamma discrimination Figure of Merit FOM) Researchers at Sandia National Laboratories have developed an organic glass scintillator OGS) material that is greatly superior to EJ276, with properties approaching those stilbene, and that can also be cast into near-final shapes, promising low production costs. By coupling OGS to a novel silicon photomultiplier SiPM) array, we intend to develop long NEXT detector modules with a 95% packing density whose energy resolution is at least three times better than VANDLE's and has a FOM exceeding 1.0 at 100 KeVee neutron energy. In Phase I we will design and produce small SiPM arrays and use them to explore the effect of detector bar geometry on both time resolution neutron energy resolution in time-of-flight mode) and FOM, using timing and FOM algorithms developed in earlier work at XIA. Our intent is to produce an optimized bar design, show that it leads to significant improvements over the best prototype designs to date, and produce a Phase II detector module design that fully meets NEXT's neutron detector needs. With an eye toward commercialization, our Sandia collaborators will both produce our test sample and also investigate improved casting and surface finishing techniques for lowering bar production costs. A successful project will lead to sales of OGM material and SiPM arrays in detectors, detector modules, and complete instruments. Detectors type will range from small forms for R&D purposes to larger volumes for portal monitors detector. Detector modules, including SiPM arrays, will include NEXT detectors and other custom applications. Complete instruments, combining detector modules with XIA's processing electronics, are suitable for neutron monitors in proton beam therapy. Benefits to society will include improved R&D opportunities in the nuclear sciences, increased security against nuclear threats, improved medical procedures, and economic enhancements to both out local economy and the nation's balance of trade due to overseas sales.