Introduction
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A unique feature of the space radiation environment is the presence of galactic cosmic rays (GCRs) and solar particle events (SPEs
). GCRs are the most abundant particles in the universe and are believed to be accelerated in the vicinity of the supermassive black hole at the center of the Milky Way. The GCRs are composed of protons, alpha particles, and heavier nuclei. The flux of GCRs is about $10^{11