Tunable Wavelength, High Efficiency Scintillator for Neutron Crystallography

DESCRIPTION (provided by applicant): Despite their unique advantages and great promise for elucidating the structure of proteins, neutron techniques have been underutilized compared to X-ray measurement techniques, primarily because of the lack of adequate neutron sources and suitable imaging detectors. The former limitation has now been effectively addressed, at least regionally, by the development of intense pulsed neutron sources such as the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory. The latter limitation, however, remains a challenge, and improved detectors will play a vital role in the effective utilization of new and existing neutron sources by facilitating many important studies. While highly promising new designs of detectors now exist, they are nonetheless limited by current neutron-sensitive scintillators that are used as converters. New and efficient scintillators that can match the performance of these novel readouts are critically important to realize the full benefit of new neutron sources. To address these limitations we propose to develop a novel scintillator with tunable emissions that can be matched to the individual performances of new high resolution, high frame rate readouts. The key component in this scintillator development is a quantum dot wavelength shifter that will allow unprecedented color matching between scintillator emissions and quantum efficiencies of individual photosensors to optimize overall detection efficiency. Our novel scintillator will attain high neutron detection efficiency with low sensitivity to gamma rays and fast temporal response, and will demonstrate the tremendous potential of nanomanufacturing -techniques to significantly improve performance and dramatically reduce production cost. Commercialization efforts will be undertaken in collaboration with an industrial partner who has well-established production capabilities and marketing groups around the globe. Specific aims. The goal of the Phase I research is to optimize the synthesis of scintillators incorporating quantum dots as very high efficiency tunable wavelength shifters to match the absorption characteristics of novel imaging photodetectors. Structured scintillators will also be fabricated from these wavelength-shifted neutron sensors and optically integrated with imaging instruments. Several scintillator specimens will be produced using optimized fabrication parameters, and then thoroughly evaluated to quantify their optical, scintillation and imaging properties for comparison with current scintillators to demonstrate the usefulness of this approach. PUBLIC HEALTH RELEVANCE: High-performance neutron detectors are critically important for neutron scattering studies that investigate the structure of proteins to advance biomedical research. Many other applications such as neutron imaging, nuclear and high energy physics research, medical imaging, diffraction, nuclear waste clean-up, nuclear treaty verification and safeguards, as well as geological exploration would benefit from advances in new technologies for detecting neutrons. The proposed research seeks to improve the light output for a neutron-sensitive plastic scintillator that can detect neutrons with high sensitivity and fine spatial resolution.