Collaborative Research: Equipment: MRI Consortium: Track 2 Development of a Next Generation Fast Neutron Detector

对富中子原子核的研究可以揭示质子和中子在核内如何相互作用的影响。这些在宇宙中元素的形成中起着重要作用，并帮助科学家了解原子的核芯是如何形成的。研究这些处于稳定边缘的核的方法之一是测量它们的分裂产物，其中包括不需要将较小的核保持在一起的中子。 中子的探测是具有挑战性的，因为它们不带电荷，只与原子的核芯相互作用。该奖项将支持基于塑料闪烁体的模块化阵列的开发，建造和调试，用于检测快速（光速的三分之一至一半）中子。与目前的中子探测器相比，新的探测器阵列将大大提高我们确定中子位置的精确度，因为它将利用最先进的光电传感器，从而实现上级精度的核结构测量。探测器模块将在七所参与的本科院校进行大规模的建造和测试，使本科生能够学习关键的技术技能，并以有意义的方式为核物理研究做出贡献。闪烁探测器是一种测量亚原子粒子在探测器内相互作用产生的闪烁光的探测器，广泛应用于科研、工业和医学成像领域，因此这些技术可以应用于许多关键领域。当代快中子探测器使用传统的探测器配置，即由光电倍增管（PMT）对读出的长塑料闪烁体棒。中子相互作用的位置是从由每个PMT在检测器棒的相对端处测量的信号的时间差推导出的，并且从哪个检测器棒被击中。一种不同的方法来收集闪烁光追求在这个新的探测器使用硅光电倍增器（SiPMs）的阵列，克服了目前的设计的局限性，并导致提高位置分辨率的快中子探测。这也允许平铺设计，其在根据特定实验需要调整阵列的有效区域方面提供更大的灵活性。氧以外的元素中子非束缚态的不变质量光谱学需要这样一个具有改进分辨率的实验装置。当你移动到更重的未束缚系统时，你将面对更高层次的密度。为了在重建的衰变能谱中分辨这些，需要更高的动量（以及因此的位置）分辨率。高位置分辨率还提高了双散射事件的辨别力，并允许使用稀有同位素束设施（如稀有同位素束设施）提供的更高束能量。完成的仪器将服务于广泛的FRIB用户社区，并使不变的质量测量的分辨率，这是需要更重和更奇特的同位素，可与FRIB beams.This奖项反映了NSF的法定使命，并已被认为是值得的支持，通过评估使用基金会的智力价值和更广泛的影响审查标准。

The study of neutron-rich atomic nuclei can reveal effects about how protons and neutrons interact inside nuclei. These play an important role in the formation of the elements in the universe and help scientists understand how the nuclear core of atoms form. One of the ways to investigate these nuclei at the edge of stability is to measure their breakup products, which includes the neutrons that are not needed to hold the smaller nuclei together. The detection of neutrons is challenging because they have no charge and only interact with the nuclear core of atoms. This award will support the development, building, and commissioning of a modular array based on plastic scintillator for the detection of fast (between one third and one half the speed of light) neutrons. The new detector array will significantly improve how precisely we can determine the neutrons’ position compared to current neutron detectors because it will make use of state-of-the-art photo-sensors, and as a result enable nuclear structure measurements with superior precision. The detector modules will be built and tested to a large extent at the seven participating undergraduate institutions, allowing undergraduate students to learn key technical skills and to contribute to nuclear physics research in a meaningful way. Scintillation detectors, i.e. detectors that measure the scintillation light that stems from subatomic particles interacting within the detector, are widely employed in research, industry, and medical imaging, so these skills can be applied in many crucial fields.Contemporary fast neutron detectors use conventional detector configurations of long plastic scintillator bars read out by pairs of photo-multiplier tubes (PMTs). The position of the neutron interaction is deduced from the time difference of the signals measured by each PMT at opposite ends of the detector bar, and from which detector bar has been hit. A different approach to scintillation-light collection is pursued in this new detector using arrays of Silicon Photo-Multipliers (SiPMs), overcoming the limitations of current designs and resulting in improved position resolution for fast neutron detection. This also allows a tiled design that offers much more flexibility in adjusting the active area of the array to specific experiment needs. Invariant-mass spectroscopy of neutron-unbound states in elements beyond oxygen requires such an experimental setup with improved resolution. As one moves to heavier unbound systems one faces higher level densities. To resolve these in the reconstructed decay energy spectrum requires higher momentum (and thus position) resolution. A high position resolution also improves the discrimination of double-scattered events and allows the use of higher beam energies that are available at the rare-isotope beam facilities such as the Facility for Rare Isotope Beams (FRIB). The completed instrument will serve the broad FRIB user community and enable invariant mass measurements at the resolution that is required for heavier and more exotic isotopes that are available with FRIB beams.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.