Cosmic-ray Physics with IceCube

IceCube 是位于南极的中微子观测站。它由 5000 多个数字光学模块组成，位于南极冰川黑暗、透明的冰层深处 1.45 至 2.45 公里之间。每个模块包括一个 10 英寸光电倍增管、一台机载计算机和相关电子设备，所有这些都包含在玻璃压力球内，并通过电线连接到中央数据采集系统。 IceTop 是 IceCube 的表面组件，在每条井下电缆的顶部附近都有一对充满冰的储罐。每个储罐都配备了两个集成到整个 IceCube 数据采集系统中的模块。当带电粒子穿过冰时，无论是在冰立方深处还是在表面储罐中，它们都会产生闪光并被数字记录。该奖项将为特拉华大学小组研究 IceCube 探测到的高能宇宙射线事件提供支持。 IceCube 作为宇宙射线探测器的新颖特点是它能够研究 IceTop 和 IceCube 深部探测器同时观察到的事件。深层探测器中的信号与表面信号的比率对初级宇宙辐射中不同原子核组的相对浓度敏感，该高能量范围无法直接测量。这项工作的一个特别重点是寻找从银河宇宙射线到银河外来源的更高能量粒子群的转变。这两个群体可以通过它们的组成和能谱来区分。研究结果将有助于理解自然界中高能粒子的来源和加速机制。更广泛的影响：本科物理学生参与校准程序以及创建处理、触发和重建算法。当他们学习相关的基本粒子物理学和电子学时，他们为该项目做出了重大贡献。在 IceCube 的建设阶段，特拉华大学创建了一个网站，提供与当地学校的接口。该网站将进行更新，重点关注科学，特别是来自表面探测器的近实时数据流，以及这些数据如何追踪太阳活动和太空天气的解释。

IceCube is a neutrino observatory at the South Pole. It consists of more than 5000 digital optical modules between 1.45 and 2.45 km deep in the dark, clear ice of the Antarctic glacier. Each module includes a 10 inch photomultiplier, an onboard computer, and associated electronics, all contained inside a glass pressure sphere and connected by wires to the central data acquisition system. IceTop is the surface component of IceCube, with a pair of ice-filled tanks near the top of each down-hole cable. Each tank is instrumented with two modules integrated into the overall IceCube data acquisition system. As charged particles pass through the ice, whether deep in IceCube or in the surface tanks they generate flashes of light that are digitally recorded. This award will provide support for the University of Delaware group to study the high-energy cosmic-ray events detected by IceCube. The novel feature of IceCube as a cosmic-ray detector is its ability to study events seen in coincidence by both IceTop and the deep detectors of IceCube. The ratio of signal in deep detectors to signal on the surface is sensitive to the relative concentration of different groups of nuclei in the primary cosmic radiation in a high energy range not accessible to direct measurements. A particular emphasis of this work is to search for a transition from galactic cosmic rays to a higher energy population of particles from extra-galactic sources. The two populations would be differentiated by their composition and energy spectra. The results will contribute to understanding the sources and acceleration mechanisms of high energy particles in Nature.Broader Impact: Undergraduate physics students are involved in the calibration procedure and in creating processing, triggering and reconstruction algorithms. They make significant contributions to the project as they learn the related elementary particle physics and electronics. During the construction phase of IceCube, a web site was created at the University of Delaware that provided an interface with local schools. The site will be updated to focus on science, particularly the near real time stream of data from the surface detectors along with an explanation of how these data trace solar activity and space weather.