A simple Local Interstellar Spectrum model to fit the proton fluxes measured by the AMS and PAMELA detectors

Abstract

In this paper we discuss some simple analytical models to fit the cosmic-ray (CR) proton data collected by the AMS detector in June 1998 and by the PAMELA detector in several campaigns covering the period 2006-2009. The CR proton spectrum at Earth is derived starting from the model of the local interstellar spectrum (LIS) and folding it with the solar modulation potential in the force field approximation. The data are well described by a LIS modeled with a simple power law particle momentum density.