The Elemental Composition of Quiet Time Low Energy Cosmic Rays Measured on the Voyager Spacecraft

Abstract

We have used the large collecting area of the Voyager telescopes to obtain greatly improved statistics on the elemental composition of quiet time low energy cosmic rays above ~3MeV/nuc. Three quiet time periods totaling 115 days between August, 1977 and February, 1978 are used. These quiet times are further subdivided into still quieter periods totaling 47 days. At low energies, the most prominent feature is the anomalous component which has a peak intensity at ~6 MeV/nuc. It is observed most prominently for N, 0 and Ne nuclei, but we believe it has been identified for the first time for C, Mg and Si nuclei as well at a much lower intensity level. This component undergoes strong solar modulation effects, and also for 0 nuclei at least, shows 27 day enhancements associated with enhanced intensities of ~0.5 MeV protons

Files

Additional details