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

合作研究：设备：MRI 联盟：下一代快中子探测器的 Track 2 开发

• 批准号: 2320405
• 负责人: James Brown
• 金额: $ 42.47万
• 依托单位: Wabash College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-15 至 2026-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2320405&HistoricalAwards=false
• 关键词: Collaborative; Research; Equipment; MRI; Consortium

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.

对富含中子的原子核的研究可以揭示质子和中子在原子核内如何相互作用的影响。这些元素在宇宙中元素的形成过程中发挥着重要作用，有助于科学家了解原子核是如何形成的。研究这些处于稳定边缘的原子核的方法之一是测量它们的分解产物，其中包括将较小的原子核聚集在一起不需要的中子。中子的探测具有挑战性，因为它们不带电荷，只与原子核相互作用。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，以探测快速(在三分之一到一半光速之间)中子。与目前的中子探测器相比，新的探测器阵列将显著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，因此能够以更高的精度测量核结构。探测器模块将在七个参与的本科院校进行很大程度的建造和测试，使本科生能够学习关键技术技能，并以有意义的方式为核物理研究做出贡献。闪烁探测器，即测量探测器内部亚原子粒子相互作用产生的闪烁光的探测器，广泛应用于研究、工业和医学成像，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由成对光电倍增管(PMT)读出的长塑料闪烁棒的传统探测器配置。中子相互作用的位置是从每个PMT在探测器棒的相反两端测量的信号的时间差中推断出来的，并且探测器棒是从哪个探测器棒被击中的。使用硅光电倍增器(SiPM)阵列的这种新探测器采用了一种不同的闪烁光收集方法，克服了当前设计的局限性，并提高了快中子探测的位置分辨率。这也允许瓷砖设计，在调整阵列的有源面积以满足特定实验需要方面提供更大的灵活性。氧以外的元素中中子非束缚态的不变质谱学需要这样一个分辨率更高的实验装置。当你移动到更重的非束缚系统时，你会面临更高的水平密度。要在重建的衰变能谱中解决这些问题，需要更高的动量(和位置)分辨率。高位置分辨率还改善了对双重散射事件的区分，并允许使用稀有同位素束流设施(FRIB)等稀有同位素束流设施可用的更高束流能量。完成的仪器将服务于广大的FRIB用户社区，并能够以FRIB光束提供的更重和更奇异的同位素所需的分辨率进行恒定质量测量。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。