MRI Consortium: Development of an Array of Germanium Detectors for COHERENT at the Spallation Neutron Source

世纪的主要学术成就之一是粒子物理学标准模型（SM）的发展。该模型成功地将当时已知的所有基本粒子分类为具有相似量子特性的组的层次结构。到目前为止，这个模型的有效性被欧洲核子研究中心大型强子对撞机上发现的希格斯玻色子所证实。然而，目前存在的标准模型留下了许多关于宇宙的问题，包括为什么希格斯质量具有它的价值以及为什么宇宙中没有反物质等基本问题。对于这些和其他关于宇宙的开放性问题，它是如何形成的，以及为什么它是这样的，寻找答案的主要领域之一是专注于中微子性质的研究，并利用我们所知道的和可以了解的关于中微子的知识作为超越标准模型（BSM）的科学探针。标准模型预测有三种不同类型的中微子，它们都没有质量，通过它们与物质相互作用时所经历的不同相互作用可以区分。但是最近的测量已经完全改变了我们对中微子的看法。我们现在知道中微子确实有质量，因为它们有质量，它们实际上可以从一种类型变成另一种类型。 此外，实验测量表明可能存在另一种类型的无菌中微子。 详细测量这些不寻常粒子的相互作用是探索标准模型之外新物理的最有前途的方法之一。该项目由COHERENT合作小组的成员领导，该小组是第一个观察到相干弹性中微子-核散射的小组。 这种反应在20世纪70年代早期就被预测到，而在近半个世纪之后，由于高灵敏度、低噪音仪器和极高束流通量的进步，例如在橡树岭国家实验室的Spiritual中子源设施中，这种反应已经被观察到。 为了理解这个过程的本质，必须研究一系列的核靶，因为散射的横截面近似与靶核中中子数的平方成比例。 通过这项MRI奖，来自杜克大学、北卡罗来纳州大学和北卡罗来纳州中央大学的研究小组将建造并运行一个锗（Ge）探测器，可以验证该探测器的中子依赖性。 锗是一个自然的选择，这种材料提供了出色的能量灵敏度。在更广泛的背景下，锗仪器将在这里开发的核反应堆监测的应用潜力。 仪器的开发将为博士后和学生在低能反冲测量的技术挑战性研究技术方面提供丰富的经验。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

One of the major intellectual achievements of the 20th century was the development of the Standard Model (SM) of particle physics. This model succeeded in classifying all of the elementary particles known at the time into a hierarchy of groups having similar quantum properties. The validity of this model to date was confirmed by the discovery of the Higgs boson at the Large Hadron Collider at CERN. However, the Standard Model as it currently exists leaves open many questions about the universe, including such fundamental questions as to why the Higgs mass has the value it has and why there is no antimatter in the universe. One of the primary areas to search for answers to these and other open questions about the universe, how it came to be, and why it is the way it is, is to focus on a study of the properties of neutrinos and to use what we know and can learn about neutrinos as probes of science Beyond the Standard Model (BSM). The Standard Model predicted that there were three different kinds of neutrinos, all massless, that were distinguishable through the different interactions that they undergo whenever they interact with matter. But recent measurements have totally changed our picture of neutrinos. We now know that neutrinos do have a mass and because they do, they can actually change from one type to another. Additionally, experimental measurements have indicated the possibility of yet an additional type of sterile neutrino. Detailed measurements of the interactions of these unusual particles are one of the most promising ways to probe for new physics beyond the Standard Model.This project is led by group members of the COHERENT collaboration that has been the first to observe Coherent elastic neutrino-nucleus scattering. The reaction was predicted in the early 1970s and has now been observed nearly a half century later, given the advances in highly-sensitive, low-noise instrumentation and very high beam fluxes, for example at the Oak Ridge National Laboratory Spallation Neutron Source facility. To understand the nature of this process, a range of nuclear targets must be studied, as the cross section for the scattering scales approximately with the square of the number of neutrons in the target nuclei. Through this MRI award, the group from Duke, North Carolina State and North Carolina Central Universities will build and then operate a Germanium (Ge) detector for which the neutron dependence of the cross section can be verified. Germanium is a natural choice for such a measurement given the excellent energy sensitivity afforded by this material.In the broader context, the Ge instrumentation to be developed here has the potential for applications in nuclear reactor monitoring. And the instrumentation development will provide extensive experience for post docs and students in the technically challenging research techniques of low-energy recoil measurements.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.