Precision Measurement of the Proton Flux in Primary Cosmic Rays from 1 GV to 1.8 TV with the Alpha Magnetic Spectrometer on the International Space Station

TL;DR

This paper reports a precise measurement of primary cosmic ray proton flux over a wide rigidity range, revealing a smooth spectrum with a gradual spectral hardening at high energies, and discusses solar effects.

Contribution

It provides the most accurate proton flux measurements from 1 GV to 1.8 TV using the AMS on the ISS, with detailed spectral index analysis.

Findings

Proton flux is smooth with no sharp features.

Spectral index hardens at high rigidities.

Solar effects influence the flux measurements.

Abstract

A precision measurement of the proton flux in primary cosmic rays with rigidity from 1 GV to 1.8 TV is presented based on 300 million events. The results show that the proton flux is smooth and exhibits no sharp structures with rigidity. The detailed variation with rigidity of the flux spectral index is presented. The spectral index is progressively hardening at high rigidities. Solar effects are also discussed.