Air showers in IceCube

冰立方中的空气骤雨：冰立方和冰顶(ANT-0602679)的数据分析从外层空间到达地球的基本粒子是来自高能天体物理来源的信号，如爆炸的恒星和大质量黑洞。被称为宇宙射线的高能粒子被冲击波和其他与释放大量引力能量相关的湍流过程加速，这也导致在可见光、X射线和其他波长的电磁光谱中出现壮观的显示。这项研究的重点是分析数据，从而更好地了解产生最高能量宇宙粒子的特定类型的源和机制。目前正在国家科学基金会的阿蒙森-斯科特南极站建设的冰立方中微子天文台将利用南极冰川的透明深冰作为探测弱相互作用中微子的大目标，这些中微子预计也来自某些宇宙射线源，但到目前为止还没有发现。中微子天文台建成后，将由4800个光学模块组成，监测超过一立方公里的冰上中微子相互作用的闪光特征。冰立方中的中微子的主要特征将是穿透地球的中微子向上移动的事件。冰立方表面包括一组探测器，这些探测器对冰立方上方大气中宇宙射线相互作用产生的穿透介子的下行背景起到了部分否决权。名为IceTop的表面阵列将由160个冰罐组成，每个冰罐都配备了两个标准的IceCube光学模块，以探测大气中高能宇宙射线相互作用产生的次级粒子阵雨。这笔赠款支持的分析将侧重于表面阵列和深部探测器同时探测到的宇宙射线事件。深信号与表面信号的比率可以用来测量重宇宙射线(如铁核)与轻宇宙射线(如质子)在气球或航天器上携带的探测器无法直接观测到的能量区域中的相对比例。特别是，我们将寻找从我们银河系内部的源到更高能量的银河系外的源的转换的特征特征。我们还将分析无线电冰切伦科夫实验同时获得的数据，寻找与冰顶的重合，以此作为将我们的研究扩展到更高能量的一种方式。截至2006年，IceCube在冰层中有9串60个探测器，有32个IceTop水箱在运行。它已经是同类探测器中最大的，随着建设的进行，分析将开始。在这笔赠款的过程中，我们将巩固和改进我们的外展工作，使其成为一个连贯的计划。我们将从创建一个关于科学和技术的网页开始，并与IceCube的照片和视频收集建立联系。然后，我们将正式并扩展我们目前为K-12学生和公众提供的临时讲座计划。

Air showers in IceCube: Analysis of data from IceCube and IceTop (ANT-0602679)Elementary particles reaching Earth from outer space are signals from energetic astrophysical sources such as exploding stars and massive black holes. The high-energy particles, called cosmic-rays, are accelerated by shock waves and other turbulent processes associated with the release of massive amounts of gravitational energy, which also lead to spectacular displays in visible light, X-rays, and other wavelengths of the electromagnetic spectrum. The focus of this research is on analysis of data that will lead to a better understanding of the specific types of sources and mechanisms that are responsible for the highest energy cosmic particles.The IceCube Neutrino Observatory, now under construction at the National Science Foundation's Amundsen-Scott South-Pole Station, will use the clear, deep ice of the Antarctic glacier as a large target for detecting weakly interacting neutrinos, which are also expected from certain cosmic-ray sources, but which have so far not been found. The neutrino observatory, when complete, will consist of 4800 optical modules monitoring more than a cubic kilometer of ice for flashes of light characteristic of neutrino interactions. The primary signature for a neutrino in IceCube will be an upward-moving event from a neutrino that has penetrated the Earth. IceCube includes an array of detectors on the surface that serve as a partial veto for the down-going background of penetrating muons created by cosmic-ray interactions in the atmosphere above IceCube. The surface array, called IceTop, will consist of 160 tanks of ice, each instrumented with two standard IceCube optical modules, to detect showers of secondary particles generated by interactions of high-energy cosmic rays in the atmosphere. The analysis supported by this grant will focus on cosmic-ray events detected in coincidence by both the surface array and the deep detectors. The ratio of deep signal to surface signal can be used to measure the relative fraction of heavy cosmic rays (e.g. nuclei of iron) to light cosmic rays (e.g. protons) in an energy region not accessible to direct observation with detectors carried above the atmosphere on balloons or spacecraft. In particular we will look for a characteristic signature of a transition from sources inside our Milky Way Galaxy to extra-Galactic sources at higher energy. We will also analyze data taken simultaneously by the Radio Ice Cherenkov Experiment, looking for coincidences with IceTop as a way of extending our research to still higher energy. As of 2006, IceCube has 9 strings of 60 detectors each in the ice, and there are 32 IceTop tanks in operation. It is already the largest detector of its kind, and analysis will start as construction proceeds.During the course of this grant we will consolidate and improve our outreach efforts into a coherent program We will start by creating a web page about the science and techniques, with connections to the IceCube photo and video collection. Then we will formalize and extend our current program of occasional lectures for K-12 students and the public.