WoU-MMA: Cosmic-Ray Physics with IceCube

WoU-MMA：使用 IceCube 进行宇宙射线物理学

• 批准号: 2209483
• 负责人: Frank Schroeder
• 金额: $ 200万
• 依托单位: University of Delaware
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2209483&HistoricalAwards=false
• 关键词: WoU; MMA; Cosmic; Ray; Physics

This award provides funding for scientists at six U.S. institutions (three of them in EPSCoR jurisdictions) to perform scientific analysis of cosmic-ray data from the IceCube Neutrino Observatory located at the U.S. Amundsen-Scott South Pole Station. The IceCube detector features one cubic kilometer of natural ice (at the depth from 1.4 to 2.4 km) that has been transformed into a giant particle detector. This is complemented by a surface array of 162 particle detectors called IceTop. Both the in-ice and surface array detect ultra-short light flashes from particle cascades initiated when high-energy cosmic rays hit the atmosphere. Complementary to IceCube’s main mission as a neutrino observatory, this world-unique setup enables scientific progress in understanding the origin of Galactic cosmic rays of highest energies and the particle physics in the atmospheric cascades. In addition to research aimed at fundamental progress in cosmic-ray physics, this award also supports scientific broader impacts through IceCube’s cosmic-ray measurements, such as heliospheric, solar, and atmospheric science, since stratospheric and solar events can impact the cosmic-ray flux measured by IceCube. Thus, this award addresses and advances the science objectives and goals of NSF's "Windows on the Universe: The Era of Multi-Messenger Astrophysics" program as well as those of the Polar program. The mystique of the South Pole environment and the compelling science of IceCube are an alluring mix. Besides its extensive coverage in newspapers and publications popularizing science, IceCube has a significant presence on social media and the World Wide Web. Through successful high school MasterClasses as well as student engagement in the scientific research, this project contributes to the education of a diverse STEM workforce. With its three-dimensional layout, the IceTop surface array above the cubic-kilometer deep optical grid, the IceCube Neutrino Observatory is also an excellent detector for cosmic-ray air showers. The combination of electromagnetic particles and low-energy muons at the surface and TeV to PeV muons by the deep in-ice grid makes IceCube a world-unique instrument for the most energetic Galactic cosmic rays. Complementing IceCube’s multimessenger mission, this setup is used to measure the cosmic-ray energy spectrum and composition in the energy range where the still-enigmatic transition between Galactic and extragalactic cosmic rays is presumed to occur. IceCube is also providing the first and world’s most sensitive measurements of little understood cosmic-ray anisotropies in the Southern Hemisphere at TeV to PeV energies. Combining data with the HAWC gamma-ray observatory in Mexico, IceCube has also compiled the first full-sky cosmic ray anisotropy observation at 10 TeV. Plans to provide combined observations at higher energies and with other experiments such as LHAASO are underway. IceCube also plays a leading role in scrutinizing hadronic interaction models of the particle physics in air showers, in particular, the forward production of leptons. By this, IceCube will contribute to the understanding of the muon puzzle, a mismatch between the measured muon content of air showers and the one predicted by state-of-the-art hadronic interaction models. To continue IceCube’s leading role in this energy range of cosmic-ray physics, a number of improvements in the analysis will be implemented to increase both the statistics and accuracy of our data. The significant increase in statistics results from additional data collection time with the complete detector, but also from expanding the analyzable data phase space to include uncontained and more inclined events. New event reconstructions applying machine-learning techniques will be developed and employed to analyze the surface and deep signals. Higher accuracy will also result from implementing a better model to account for snow on the IceTop tanks, as well as cross-checks with prototype enhanced surface instrumentation. These improvements will drive IceCube’s cosmic-ray mission by providing higher sensitivity and resolution Taken together, they provide a path to follow to continue IceCube’s contribution to understanding the physics and origin of highest energy Galactic cosmic rays.This project is jointly funded by the IceCube Research Support and Particle Astrophysics - Cosmic Phenomenon programs in MPS's Division of Physics, the Antarctic Astrophysics and Geospace Sciences program in GEO's Office of Polar Programs, the Established Program to Stimulate Competitive Research (EPSCoR), and the NSF Big Ideas: Windows on the Universe - Multimessenger Astrophysics.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该奖项为六个美国机构的科学家提供资金（其中三个在EPSCoR管辖范围内），对位于美国阿蒙森-斯科特南极站的IceCube中微子天文台的宇宙射线数据进行科学分析。IceCube探测器拥有一立方公里的天然冰（深度从1.4到2.4公里），已经被改造成一个巨大的粒子探测器。这是由162个粒子探测器组成的表面阵列，称为IceTop。冰内和表面阵列都探测到高能宇宙射线撞击大气层时引发的粒子级联产生的超短闪光。作为对IceCube作为中微子观测站的主要使命的补充，这个世界上独一无二的设置使科学进步能够理解最高能量的银河宇宙射线的起源和大气级联中的粒子物理学。除了旨在宇宙射线物理学取得根本性进展的研究外，该奖项还支持通过IceCube的宇宙射线测量产生更广泛的科学影响，例如日光层，太阳和大气科学，因为平流层和太阳事件可以影响IceCube测量的宇宙射线通量。因此，该奖项解决并推进了NSF的“宇宙之窗：多信使天体物理学时代”计划以及极地计划的科学目标和目标。南极环境的神秘性和冰立方令人信服的科学性是一个诱人的组合。除了在普及科学的报纸和出版物上的广泛报道外，IceCube在社交媒体和万维网上也有重要的影响力。通过成功的高中大师班以及学生参与科学研究，该项目有助于教育多元化的STEM劳动力。 冰立方中微子天文台的三维布局，冰顶表面阵列位于一千米深的光学网格之上，也是宇宙射线空气簇射的优秀探测器。冰立方表面的电磁粒子和低能μ子与冰中深层网格的TeV到PeV μ子的结合，使冰立方成为世界上独一无二的最具能量的银河宇宙射线仪器。作为对冰立方多信使使命的补充，该装置用于测量宇宙射线能谱和能量范围内的成分，在该能量范围内，银河系和河外宇宙射线之间的过渡被认为是神秘的。冰立方还提供了第一个和世界上最灵敏的测量很少了解宇宙射线各向异性在南半球在TeV到PeV的能量。结合墨西哥HAWC伽马射线天文台的数据，IceCube还编制了第一个10 TeV的全天空宇宙射线各向异性观测。计划提供更高能量的组合观测，并与其他实验，如LHAASO正在进行中。冰立方还在审查空气簇射中粒子物理学的强子相互作用模型方面发挥着主导作用，特别是轻子的向前产生。通过这一点，IceCube将有助于理解μ子之谜，即测得的空气簇射的μ子含量与最先进的强子相互作用模型预测的μ子含量之间的不匹配。为了继续IceCube在宇宙射线物理学的这一能量范围内的主导作用，将对分析进行一些改进，以增加我们数据的统计和准确性。统计数据的显著增加是由于完整检测器的额外数据收集时间，而且还由于扩展可分析数据相空间以包括未包含和更倾斜的事件。将开发应用机器学习技术的新事件重建，并用于分析表面和深层信号。更高的准确性也将来自于实施一个更好的模型来解释IceTop坦克上的雪，以及与原型增强型表面仪器的交叉检查。这些改进将通过提供更高的灵敏度和分辨率来推动IceCube的宇宙射线使命。总的来说，它们为IceCube继续为理解最高能量银河宇宙射线的物理和起源做出贡献提供了一条途径。该项目由MPS物理部的IceCube研究支持和粒子天体物理学-宇宙现象项目共同资助，GEO极地计划办公室的南极天体物理学和地球空间科学计划，刺激竞争性研究的既定计划（EPSCoR）和NSF大创意：宇宙之窗-多信使天体物理学奖。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值进行评估，被认为值得支持和更广泛的影响审查标准。