Energy spectrum of primary cosmic rays between 10^14.5and 10¹⁸eV

Simple hadronic cascade simulations

“…Furthermore, these results are in very good agreement with the experimental results reported by the Akeno group [9]. On the other hand; the results obtained with J = 1 and 2 have values for β that are too low, especially for J = 1.…”

Ultra-high energy cosmic ray investigations by means of EAS muon density measurements

“…This spectrum is close to MSU spectrum [10] as given in [11], it is not very much different from the Akeno data [12] around the knee, and is in a reasonable agreement with Fly's Eye "stereo" results [13] around 10 18 eV. To check the sensitivity at highest energies, calculations with the ankle at 3 EeV have been also performed.…”

Changes of the cosmic-ray mass composition in the 1014–1016 eV energy range

“…A particularly simple model of the cosmic-ray composition is to assume that there is only one universal type of Galactic cosmic-ray sources and the acceleration time scales as well as the propagation are then only functions of the rigidity R = pc/Ze (p being the momentum). It is well known that such a simple model cannot be matched very well to the older Akeno measurements [22] where the knee appears almost as a single kink in the flux spectrum. The newer Tibet array measurements [23] with a gradual steepening of the spectrum are much closer to expectations for a minimal model but still the steepening of the spectrum has to happen within less than about half a decade of rigidity.…”

“…Such a simple model is consistent with our composition data alone (for R knee ≈ 100 TV, see model 2 in figure 11) or with the flux data of JACEE and the Tibet array [23] alone (for R knee ≈ 500 TV, see model 1 in figure 9) but could not be tuned to be consistent with both our composition data and the available flux data. This inconsistency is even more severe if the Akeno flux spectrum [22] is assumed. Such a simple model is also inconsistent with JACEE composition measurements finding a harder spectrum for the CNO and iron groups of nuclei than for protons and helium near 100 TeV.…”

“…The bias of air-shower [24], JACEE [17] and Akeno [22] experiments. Note that differences of the order of 30% between absolute flux scales by different experiments are consistent with their estimated energy scale errors.…”