Cosmic Ray Analysis and Simulation of IceTop and IceCube Data

University Of Alaska Anchorage Campus, Anchorage AK

Investigators

Abstract

It has been over 100 years since the discovery of the energetic particles from space known as "cosmic rays." Comprised of a variety of particle types, cosmic rays arrive at Earth with a wide range of energies. High energy cosmic rays are composed of atomic nuclei, ranging in mass from protons up to iron. Just what percentage of the population is light, and what percentage is heavy, is still under active study. Because cosmic rays are charged and their trajectories bend in magnetic fields, they do not point back to their origin; determining the origin of these particles is an unsolved problem with a 100-year heritage. Features in the energy spectrum (such as kinks, bumps, or changes in slope) are important clues, thought to be related to changes in composition and origin. The goal of this project is to measure the composition and energy spectrum of cosmic rays by using data from IceTop, the surface component of the IceCube Observatory located at the Amundsen-Scott South Pole Station in Antarctica, in coincidence with IceCube data. The project has been designed to include self-contained projects appropriate for undergraduates, a unique training and learning opportunity for UAA undergraduates not only to participate in active research and discovery, but also to be an important part of a large international effort. In addition, the construction of a muon telescope and small-scale air shower array using scintillators is planned as a tool for outreach, education, and training in the field of particle astrophysics. IceTop is an 81-element extensive air-shower array located on the surface, above IceCube. This project first focuses on improving the reconstruction of cosmic ray air showers with IceTop, especially at high energies where current reconstruction techniques are underperforming. It will study snow attenuation, the curvature and fluctuations of the shower front, and the separate treatment of coincident and isolated signals in the detector. The project includes simulations to study how different hadronic interaction models impact the signals seen in IceTop. With plentiful data statistics and advanced data analysis techniques available, IceTop is capable of delivering results of relevance to the field of cosmic ray astrophysics: a detailed cosmic ray energy spectrum, and the mass composition of cosmic rays as a function of energy.