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

20世纪的主要智力成就之一是粒子物理标准模型(SM)的发展。这个模型成功地将当时已知的所有基本粒子归入具有相似量子性质的群组的层次结构中。在欧洲核子研究中心的大型强子对撞机上发现的希格斯玻色子证实了这个模型到目前为止的有效性。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，为什么宇宙中没有反物质等基本问题。寻找这些和其他关于宇宙的公开问题的答案，它是如何形成的，为什么它是这样的，主要领域之一是专注于中微子的性质的研究，并使用我们所知道和可以了解的中微子作为超越标准模型(BSM)的科学探测器。标准模型预测，有三种不同类型的中微子，它们都是无质量的，可以通过它们与物质相互作用时经历的不同相互作用来区分。但最近的测量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，所以它们实际上可以从一种类型变成另一种类型。此外，实验测量还表明了另一种类型的不孕中微子的可能性。对这些不寻常粒子相互作用的详细测量是探索超越标准模型的新物理的最有希望的方法之一。这个项目是由第一个观测到相干弹性中微子-原子核散射的相干合作小组的成员领导的。这种反应是在1970年代初预测的，鉴于高灵敏度、低噪音仪器和非常高的束流密度的进步，例如橡树岭国家实验室散裂中子源设施，现在已经观察到了近半个世纪后的情况。为了理解这一过程的本质，必须研究一系列核目标，因为散射截面的比例与靶核中中子数量的平方大致相同。通过这项核磁共振奖，来自杜克大学、北卡罗来纳州立大学和北卡罗来纳中央大学的团队将建造并操作一种锗(Ge)探测器，该探测器的横截面的中子相关性可以得到验证。鉴于锗材料所提供的优异的能量灵敏度，锗是这种测量的自然选择。在更广泛的背景下，将在这里开发的Ge仪器具有在核反应堆监测中应用的潜力。仪器设备的开发将为博士后和学生提供具有技术挑战性的低能量后坐测量研究技术的丰富经验。该奖项反映了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。

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.