MRI: Development of the ARIANNA High Energy Neutrino Telescope Instrument

MRI：ARIANNA 高能中微子望远镜仪器的开发

• 批准号: 1126672
• 负责人: Steven Barwick
• 金额: $ 91万
• 依托单位: University of California-Irvine
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-15 至 2015-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1126672&HistoricalAwards=false
• 关键词: MRI; Development; ARIANNA; Energy; Neutrino

The primary purpose of the ARIANNA Ultra-High Energy (UHE) Neutrino project is to observe ~40 cosmogenic neutrinos per year originated by the GZK mechanism with sufficient precision to determine their energy spectrum and interaction properties. The energy spectrum of GZK neutrinos provides important insight on the production mechanism and source distribution of the cosmic rays. In addition, a statistically significant measurement of the angular distribution of the diffuse cosmogenic neutrino signal can be used to infer the interaction cross-section at energies beyond those probed by Large Hadron Collider. While the physics of the GZK mechanism is straightforward (extragalactic UHE protons collide with cosmic microwave background photons, producing pions that eventually decay to neutrinos), answering how the cosmic rays were accelerated to very high energies is especially difficult because cosmic rays are bent by magnetic fields in our Galaxy, and their range is limited by the GZK mechanism to ~100 megaparcecs. There is now a long legacy of successful high-energy neutrino programs that utilize the abundant and transparent ice of Antarctica. In particular, ARIANNA relies on the detection of radio pulses generated after neutrino interactions in dense media by the Askaryan effect, capitalizing on several remarkable properties of the Ross Ice Shelf near McMurdo Station, the hub of U.S. Antarctic Program operations: (1) the ice is impressively transparent to electromagnetic radiation at radio frequencies, (2) the water-ice boundary below the shelf behaves like a good mirror to reflect radio signals from neutrinos in any downward direction, and (3) background noise levels were quite modest in the frequency band of interest. Its close proximity to McMurdo Station provides a number of suitable options for logistical support, and ARIANNA's scalable architecture allows it to follow the science. This award allows the project to develop the data acquisition electronics required by the ARIANNA autonomous stations. Experience gained in operating the hexagonal array with precision, low power electronics would frame the performance requirements needed to expand the array in the future. The project will continue contributing significantly to the training of next generation of scientists by integrating graduate and undergraduate education with technology and instrumentation development, field observations, and scientific analysis.

阿里安纳超高能中微子项目的主要目的是每年观测约40个由GZK机制产生的宇宙成因中微子，并以足够的精度确定它们的能谱和相互作用特性。GZK中微子的能谱为研究宇宙线的产生机制和源分布提供了重要的信息。此外，扩散宇宙成因中微子信号的角分布的统计显著测量可以用来推断在能量超过大型强子对撞机探测的相互作用截面。虽然GZK机制的物理学很简单（河外UHE质子与宇宙微波背景光子碰撞，产生π介子，最终衰变为中微子），但回答宇宙射线如何被加速到非常高的能量是特别困难的，因为宇宙射线被我们银河系中的磁场弯曲，并且它们的范围被GZK机制限制在~100兆秒。现在有一个长期的遗产，成功的高能中微子计划，利用丰富和透明的冰南极洲。特别是，ARIANNA依赖于通过Askaryan效应在稠密介质中中微子相互作用后产生的无线电脉冲的检测，利用了美国南极计划运营中心麦默多站附近罗斯冰架的几个显着特性：（1）冰对于无线电频率的电磁辐射是令人印象深刻的透明的，（2）冰架下方的水冰边界就像一面很好的镜子，可以反射来自中微子的无线电信号，使其向下传播;（3）在感兴趣的频段内，背景噪声水平相当适中。它靠近麦默多站，为后勤支持提供了许多合适的选择，ARIANNA的可扩展架构使其能够遵循科学。该合同使该项目能够开发ARIANNA自主台站所需的数据采集电子设备。在使用精确的低功率电子设备操作六边形阵列方面获得的经验将确定未来扩展阵列所需的性能要求。该项目将继续通过将研究生和本科生教育与技术和仪器开发、实地观察和科学分析相结合，为培养下一代科学家做出重大贡献。