EAGER: The CHANDLER Reactor Neutrino Detector

来自核反应堆的中微子在我们理解这些难以捉摸、难以观察的基本粒子的性质方面发挥了核心作用。已知存在三种不同类型的中微子，它们是通过一种已知的自然力相互作用而被探测到的。第四种类型的中微子已经被假设，一种所谓的光惰性中微子，被认为只通过重力相互作用。自20世纪90年代末，一些加速器数据被证明与粒子物理标准模型的3中微子框架不相容以来，就一直存在着这种中微子的持续存在的、未经证实的暗示。最近的结果和对旧数据的重新分析继续表明这种新物理学的存在，但没有实验能够明确地证明或排除它们的存在。展望未来，反应堆中微子提供了一种很有希望的方法来解决通常归因于轻惰性中微子的异常群。一个特别相关的提示是所谓的反应堆中微子异常，即所有反应堆实验发现中微子相互作用概率与反应堆中微子通量的计算相比存在缺陷。反应堆中微子探测技术可能有基础科学以外的应用。有人指出，具有良好能量分辨率的高效探测器可以就地测定反应堆的钚含量。这种能力可以用来评估新的反应堆设计，或者作为核不扩散核查计划的一部分。不扩散保障措施的实际应用将需要一种探测器技术，这种技术可以在地面上操作，靠近反应堆，屏蔽最少，没有危险液体。CHANDLER技术是在考虑到这些要求的情况下构思的。“钱德勒”项目将继续成为培养年轻科学家的绝佳场所。该项目还包括两名高中教师通过QuarkNET计划。光惰性中微子的发现将真正改变粒子物理领域，而彻底揭穿~ 1ev惰性中微子假说将简化对未来长基线实验的解释。该EAGER合同提供资金，通过在北安娜核电站部署80通道、80公斤MiniCHANDLER原型机，对一种名为CHANDLER的新型反应堆中微子探测器技术进行全面系统测试。此部署的目标是评估检测器的性能。特别是，它将确定MiniCHANDLER是否能够充分地从背景中分离反应堆中微子事件，以及该技术是否能够进行高精度光谱测量，从而最终发现或排除无菌中微子假说。一个成功的演示将证明该技术适用于全面的短基线中微子振荡搜索。

Neutrinos from nuclear reactors have played a central role in our understanding of the properties of these elusive, hard-to-observe fundamental particles. Three different types of neutrino are known to exist, having been detected through their interaction via one of the known forces of nature. A fourth type of neutrino has been postulated, a so-called light sterile neutrino, that is presumed to only interact via gravity. Persistent, unproven hints of such a neutrino have been around since the late 1990's, when some accelerator data were shown to be incompatible with the 3-neutrino framework of the Standard Model of Particle Physics. More recent results and re-analyses of older data continue to suggest the existence of this type of new physics, but no experiment has been able to definitively demonstrate or rule out their existence. Going forward, reactor neutrinos offer a promising means to resolve the cluster of anomalies commonly attributed to a light sterile neutrino. One hint of particular relevance is the so-called reactor neutrino anomaly whereby all reactor experiments find a deficit in the neutrino interaction probability when compared to calculations of the reactor neutrino flux. Technologies for reactor neutrino detection may have applications beyond basic science. It has been pointed out that a high-efficiency detector with good energy resolution could determine the plutonium content of a reactor in situ. Such a capability could be used to evaluate new reactor designs, or as a part of a verification scheme for nuclear non-proliferation. A real-world application to non-proliferation safeguards will require a detector technology which can operate at the surface, in close proximity to a reactor, with minimal shielding and without hazardous liquids. The CHANDLER technology was conceived with these requirements in mind. The CHANDLER project will continue to be an excellent training ground for young scientists. This project also involves two high school teachers through the QuarkNET program.The discovery of a light sterile neutrino would be truly transformative to the field of particle physics, while a thorough debunking of the ~1 eV sterile neutrino hypothesis would simplify interpretations of future long-baseline experiments. This EAGER award provides funding to perform a full systems test of a new reactor neutrino detector technology, known as CHANDLER, by deploying the 80 channel, 80 kg MiniCHANDLER prototype, at the North Anna Nuclear Power Plant. The goal of this deployment is to evaluate the detector's performance. In particular, it will determine whether MiniCHANDLER can adequately isolate reactor neutrino events from the background, and whether this technology is capable of the high precision spectral measurement required to definitively discover or rule out the sterile neutrino hypothesis. A successful demonstration will prove the suitability of this technology for a full-scale short-baseline neutrino oscillation search.