Collaborative Research: MRI-R2 Instrument Development of the Askaryan Radio Array, A Large-scale Radio Cherenkov Neutrino Detector at the South Pole

合作研究： 南极大型射电切伦科夫中微子探测器 Askaryan 射电阵列的 MRI-R2 仪器开发

• 批准号: 1002483
• 负责人: Kara Hoffman
• 金额: $ 147.78万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-01 至 2013-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1002483&HistoricalAwards=false
• 关键词: Collaborative; Research; MRI; R2; Instrument

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). One of the most outstanding questions in astronomy and astrophysics addresses the origin and evolution of the cosmic accelerators that produce the highest energy (UHE) cosmic rays. This question may be best addressed through the observation of UHE cosmogenic neutrinos that travel from their source undeflected by galactic and interstellar magnetic fields and unimpeded by interactions with the cosmic microwave background (CMB) radiation. However, uncertainties in the predicted cosmogenic neutrino fluxes make it difficult to design an array with sufficient sensitivity to collect a statistically meaningful sample of events. At very high energies (above 10^15 eV), neutrinos could be most efficiently detected in dense, radio frequency (RF) transparent media via the Askaryan effect. The abundant cold ice covering the Antarctic, with its exceptional RF clarity, has been hosting several pioneering efforts to develop this RF approach. From the expertise gained in these experiments and utilizing the infrastructure developed by the U.S. Antarctic Program, it is proposed to develop radio-listening equipment that can constitute the Askaryan Radio Array (ARA) and install it in the ice near the geographical South Pole. The primary goal of the ARA array will be establishing the absolute cosmogenic neutrino flux through the modest number of events. As the proposed radio antennae are deployed in ice holes extending below the firn layer to 200-m depth, they will have the ability to distinguish surface noise from sources originating deep in the ice cap (otherwise not possible in balloon-borne experiments). The ARA will have sufficient sensitivity to establish the presence or absence of the secondary UHE neutrinos produced by the interaction of cosmic rays with CMB. Such an observatory would also provide a unique probe of long-baseline high-energy neutrino interactions unattainable with any manmade neutrino beam. The adopted clustered geometry of the array (in which a single localized cluster may act as a standalone array) would allow trading the precise angular resolution for the increased event rates. The flux measurement and experience gained in operating the limited number of stations would frame the performance requirements needed to expand the array in the future to measure a larger number of neutrinos with greater angular precision in order to study their spectrum and origins. The project will continue contributing significantly to the training of the next generation of scientists by integrating graduate and undergraduate education with the technology and instrumentation development.

该奖项是根据2009年《美国复苏与再投资法》（公法111-5）资助的。天文学和天体物理学中最杰出的问题之一是探讨产生最高能量（UHE）宇宙射线的宇宙加速器的起源和演变。可以通过观察到宇宙中微子的观察，从其未忽视的宇宙中微子来解决这个问题。但是，预测的宇宙中微子通量中的不确定性使得很难设计具有足够灵敏度的阵列来收集统计意义的事件样本。在非常高的能量（高于10^15 eV）下，可以通过Askaryan效应以致密的射频（RF）透明培养基最有效地检测中微子。覆盖南极的大量冷冰以其出色的RF清晰度，一直在举办几项开发这种RF方法的开创性努力。从这些实验中获得的专业知识并利用美国南极计划开发的基础设施，提议开发可以构成Askaryan无线电阵列（ARA）的无线电上播放设备，并将其安装在地理南极附近的冰中。 ARA阵列的主要目标是通过适度的事件来确定绝对的宇宙中微子通量。由于所提出的无线电天线被部署在FIRN层以下至200 m深度的冰洞中，因此它们将具有将表面噪声与源自冰盖深处的源的能力区分（否则在气球传播实验中都无法实现）。 ARA将具有足够的敏感性，以确定宇宙射线与CMB的相互作用产生的次级UHE中微子的存在或不存在。这样的天文台还将提供与任何人造中微子束无法实现的长基线高能中微子相互作用的独特探针。所采用的阵列的聚类几何形状（其中单个局部群集可以充当独立阵列）将允许将精确的角度分辨率交易以增加事件速率。在操作有限数量的电台方面获得的通量测量和经验将构成扩展将来阵列所需的性能要求，以测量具有更高角度精度的大量中微子，以研究其频谱和起源。该项目将继续通过将研究生和本科教育与技术和仪器开发相结合，为下一代科学家培训做出重大贡献。