WoU-MMA: Cosmic-Ray Physics with IceCube 2025 - 2028

About This Grant

This award provides funding for scientists at six institutions in the United States to analyze cosmic rays using data gathered by the IceCube Neutrino Observatory. IceCube is a particle detector situated at the U.S. Amundsen-Scott South Pole Station consisting of one cubic kilometer of natural ice at a depth between 1.4 and 2.4 km. It is complemented by IceTop, a surface detector array. Both the ice-based and surface detectors identify ultra-short flashes of light from particle cascades that occur when high-energy cosmic rays enter the Earth atmosphere. IceCube's primary scientific mission is to obverse and characterize neutrinos, however, its unique setup is used to also improve our understanding of the origins of high-energy Galactic cosmic rays and the particle physics involved in atmospheric cascades. This award will enable fundamental research in cosmic-ray physics but will also encompass broader scientific impacts through IceCube’s cosmic-ray measurements. The intriguing environment of the South Pole combined with the exciting science of IceCube creates a captivating experience for young scientists and students. In addition to science publications, IceCube maintains a strong presence on both social media and the internet. Through high school MasterClasses and student involvement in scientific research, this project will play a key role in educating the future STEM workforce. With its three-dimensional layout the IceCube Neutrino Observatory is also an excellent detector for cosmic-ray air showers, which are atmospheric particle cascades initiated by high-energy particles from space. The combined measurement of electromagnetic particles and low-energy muons of air showers at the surface and TeV to PeV muons by the in-ice detector makes IceCube a unique instrument. It therefore makes unique contributions to the particle physics and astrophysics related to the most energetic Galactic cosmic rays. Complementing IceCube’s multi-messenger mission and neutrino astrophysics, IceCube measures various features of the Galactic cosmic-ray flux, such as its energy spectrum, mass composition, and spatial distribution. IceCube has provided 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 other observatories and studying the structure and energy dependence of the anisotropy will provide further insight to the origin of Galactic cosmic rays. Efforts for a more accurate measurement of the cosmic-ray energy spectrum will continue, focusing on reducing systematic uncertainties by improving analysis techniques and by evaluating data of new surface instrumentation deployed prior to this award. This project advances the objectives of "Windows on the Universe: the Era of Multi-Messenger Astrophysics", one of the 10 Big Ideas for Future NSF Investments. 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.