Chemical Composition and Energy Spectrum of Cosmic Rays Using the IceCube Neutrino Observatory

宇宙射线不断地轰击大气层，但关于宇宙射线产生，加速和传播过程的关键信息仍然缺乏。然而，候选理论模型已经开发出来，可以对地球上可观测到的宇宙射线参数进行可测试的预测。 为了测试这些模型，需要在整个能量范围内对宇宙射线的多个元素光谱进行精确的实验测量。 利用冰立方中微子天文台（ICNO），马奎特大学的冰立方小组将利用六年的冰立方数据，新的后LHC模拟，事件选择的新方法，减少系统误差，新的软件算法，以及新的成分敏感参数。 该小组将与更广泛的密尔沃基社区分享他们的研究，以帮助弥合美国种族隔离最严重的城市之一的种族和社会经济鸿沟。 根据该奖项，他们将走进社区，通过有趣和互动的“家庭物理”项目激励当地不同的高中生群体，并将不同的高中生带回马奎特，通过冰立方大师班让他们接触“大科学”工作机会。 为了提高高中生对物理学的认识，使其成为所有背景的学生的一条强大而可行的职业道路，这项工作将由一个跨文化能力计划来指导，以培养马奎特学生与当地社区互动和联系，提高他们自己的跨文化能力，并在物理系内建立一种同情的文化，以维持妇女和代表性不足的少数民族在物理学中的参与。ICNO是目前唯一能做到这一点的探测器这是一个非常受欢迎的测量，包括整整十年的能量，其中四个元素光谱从未被测量过。这将为从银河系到河外宇宙射线的整个过渡区提供一幅新的连贯画面。 此外，马奎特IceCube小组将模拟并全面优化本季度（2018-19）在南极部分部署的新原型闪烁体阵列的探测器响应和阵列布局，以最大限度地提高其对宇宙射线分析的有效性。 这个新阵列的设计是为了减轻雪漂移和积累的问题，威胁到目前的ICNO表面阵列（IceTop）的有效性。这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

Cosmic rays constantly bombard the atmosphere, yet key information regarding the processes of cosmic ray creation, acceleration, and propagation is lacking. However, candidate theoretical models have been developed to make testable predictions about cosmic ray parameters that are observable at Earth. In order to test these models, precise experimental measurements of multiple elemental spectra of cosmic rays are needed from a single experiment across the full energy range. Using the IceCube Neutrino Observatory (ICNO), the IceCube group at Marquette University will provide the cosmic ray community with the first measurement of the elemental spectra from four distinct mass groups from the 'knee' to the 'ankle' in the cosmic ray energy spectrum using six years of IceCube data, new post-LHC simulations, novel methods for event selection, reduced systematic errors, new software algorithms, and new composition-sensitive parameters. The group will share their research with the broader Milwaukee community to help bridge the racial and socio-economic divide in one of the most highly segregated cities in the United States. Under this award, they will go out into the community to inspire the diverse local high school student population with fun and interactive "household physics" projects and bring diverse high school students back to Marquette to expose them to "big science" job opportunities through an IceCube Master Class. In order to increase awareness among high school students of physics as a strong and viable career path for students from all backgrounds, this work will be framed by an intercultural competency program to train Marquette students to interact and connect with their local community empathetically, increase their own intercultural competency, and to build a culture of compassion within the physics department to sustain the participation of women and underrepresented minorities in physics.The ICNO is the only detector that can presently perform this highly sought measurement that includes an entire decade in energy where four elemental spectra have never been measured. This will provide a new and coherent picture across the entire transition region from galactic to extragalactic cosmic rays. Further, the Marquette IceCube group will simulate and fully optimize the detector response and array layout for a new prototype scintillator array being partially deployed at the South Pole this season (2018-19) to maximize its effectiveness for the cosmic ray analyses. This new array is designed to mitigate the problem of snow drift and accumulation that threatens the effectiveness of the current ICNO surface array (IceTop).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.