Spectra of cosmic-ray hadrons in the range 0.1–1000 GeV

Abstract

The energy spectra of cosmic-ray neutrons, protons, and pions were determined at sea level in the range 0.1 – 1000 GeV. The results are based on the measurements of the neutron-multiplicity distributions produced by cosmic hadrons in the Turku spectrometer. Below 0.5 GeV, the values γ = 1.47 ± 0.04 and 0.8 ± 0.1 were obtained for the slopes of the neutron and proton spectra. At 1000 GeV, the nucleon spectra are much steeper with γ = 2.79 ± 0.06. The pion spectrum was found to obey the power law with γ = 1.41 ± 0.05 in the low-energy region up to 30 GeV. Above 500 GeV, the spectrum of pions, containing an admixture of accompanied particles, was found to reach the high energy limit with γ = 2.92 ± 0.06.