Tunable Wavelength, High Efficiency Scintillator for Neutron Crystallography

描述（由申请人提供）：尽管中子技术具有独特的优势和阐明蛋白质结构的巨大希望，但与x射线测量技术相比，中子技术尚未得到充分利用，主要是因为缺乏足够的中子源和合适的成像探测器。由于橡树岭国家实验室（Oak Ridge National Laboratory）的散裂中子源（SNS）等强脉冲中子源的发展，前者的限制现在至少在局部得到了有效解决。然而，后一种限制仍然是一个挑战，改进的探测器将通过促进许多重要的研究，在有效利用新的和现有的中子源方面发挥至关重要的作用。虽然现在存在非常有前途的新探测器设计，但它们仍然受到当前用作转换器的中子敏感闪烁体的限制。能够匹配这些新读数性能的新型高效闪烁体对于实现新中子源的全部优势至关重要。为了解决这些限制，我们建议开发一种具有可调发射的新型闪烁体，可以与新的高分辨率，高帧率读出的单个性能相匹配。该闪烁体开发的关键组件是量子点波长移位器，它将允许闪烁体发射和单个光传感器量子效率之间前所未有的颜色匹配，以优化整体检测效率。我们的新型闪烁体将获得高中子探测效率，对伽马射线的低灵敏度和快速的时间响应，并将展示纳米制造技术在显著提高性能和显著降低生产成本方面的巨大潜力。商业化工作将与一个在全球拥有成熟生产能力和销售团体的工业伙伴合作进行。具体的目标。第一阶段研究的目标是优化闪烁体的合成，将量子点作为非常高效的可调谐波长移位器，以匹配新型成像光电探测器的吸收特性。结构闪烁体也将由这些波长移位的中子传感器制造，并与成像仪器光学集成。几个闪烁体样品将使用优化的制造参数生产，然后彻底评估，以量化其光学，闪烁和成像特性，以与当前的闪烁体进行比较，以证明该方法的实用性。公共卫生相关性：高性能中子探测器对于研究蛋白质结构的中子散射研究至关重要，从而推进生物医学研究。中子成像、核和高能物理研究、医学成像、衍射、核废料清理、核条约核查和保障以及地质勘探等许多其他应用将受益于探测中子新技术的进步。提出的研究旨在提高中子敏感塑料闪烁体的光输出，该闪烁体可以以高灵敏度和良好的空间分辨率检测中子。

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.