Calibration of Neutron Monitor Yield Functions with AMS Data

Abstract

Stars, including the Sun, shower our planet with a multitude of particles. We measure their fluxes both with space-based and ground-based detectors. Space-based detectors see more particles, but their detection area is confined to a small orbit. Ground-based detectors, especially Neutron Monitors (NMs), are cheaper and are placed across the globe. We can use them to fill in the gaps given we have an accurate way to correlate the two types of data. This thesis explored correlations between space-based and ground-based measurements. In the literature, such correlations are parametrized by Yield Functions (YFs) which are fits derived from Monte Carlo simulations of particle cascades. I compared three popular YFs (Mi20, Mi13, and Ma16) correlating AMS-02 flux spectrums with 21 NMs. I found that the Mi20 YF gives the most stable results on Bartels Rotation (27 day) averaged data. However, none of them are optimal on daily time scales, which is essential for use of NMs for space weather and other short time scale solar event analysis. In this thesis, I explore why this may be and give suggestions on how this could be corrected for in the future.