Cosmic ray spectrum obtained from the energy scattered by the particles of extensive air showers in the atmosphere and the galactic model

The differential energy spectrum of cosmic rays that is obtained on the basis of the measurements of Cherenkov radiation from extensive air showers in an energy range of 10¹⁵–10²⁰ eV is compared with the model of the propagation of primary particles in the interstellar medium with fractal properties. It is found that the shape of the experimental spectrum is in good agreement with the shape of the calculated spectrum of “all particles” at 10¹⁵–10¹⁸ eV. The average mass composition of cosmic rays that is calculated on the basis of five components does not contradict the average mass composition obtained from the experimental data for several parameters in this energy range. Original Russian Text ? S.P. Knurenko, A.A. Ivanov, A.V. Saburov, 2007, published in Pis’ma v Zhurnal éksperimental’noĭ i Teoreticheskoĭ Fiziki, 2007, Vol. 86, No. 10, pp. 709–712.     

Determining the primary cosmic ray energy from the total flux of Cherenkov light measured at the Yakutsk EAS array

We present a method for determining the energy of the primary particle that generates an extensive air shower (EAS) of comic rays based on measuring the total flux of Cherenkov light from the shower. Applying this method to Cherenkov light measurements at the Yakutsk EAS array has allowed us to construct the cosmic ray energy spectrum in the range 10¹⁵ ? 3 × 10¹⁹ eV.     

Portion of muons with a threshold energy above 1 GeV in extensive air showers with ultra-high energies,according to the Yakutsk EAS array data

Characteristics of the muon component in extensive air showers and the fluctuations of muons are considered. In this work, we compare experimental data with computations performed for various models of the hadron interactions of protons and iron nuclei. The aim of this analysis is to obtain information on the mass composition of cosmic rays in an ultra-high energy region.     

Composition of Cosmic Rays with Energy More than 0.1 EeV by Long-Term Optical Observations of Cherenkov Emission at Yakutsk EAS Array

Physics of Atomic Nuclei - The paper presents results on longitudinal development of air showers with ultra-high energies and mass composition of cosmic rays 〈ln A〉. The data is...     

Cosmic ray energy spectrum (>1017 eV) of the Yakutsk EAS array

The energy spectrum obtained on the Yakutsk array for the parameter S ₆₀₀ is compared with the results obtained on the AGASA and HiRes arrays and the latest Pierre Auger Observatory data. The discrepancy in the intensity of the energy spectra obtained in different experiments can be explained by the presence of systematic errors in shower energy estimations.     

Estimation of the PCR mass composition in the energy range 1017–1019 eV on the basis of multicomponent analysis of the characteristics of EASs detected at the Yakutsk array

The characteristics of longitudinal and radial extensive air shower development derived from the results of detection of the charged particle flux and Cherenkov light in extensive air showers at the Yakutsk array. To estimate the primary cosmic ray composition, a combination of the parameters X_max and ρ₆₀₀ and the database simulated using the CORSIKA code (QGSJET model) for showers generated by five types of nuclei (p, He, C, Si, Fe) in the energy range 10¹⁷–10¹⁹ eV were used. Application of the multicomponent method made it possible to divide the showers into three groups (p + He), C, and (Si + Fe) and estimate their percentage. The error in identifying nuclei in the energy range 10¹⁷–10¹⁸ eV does not exceed 30%.     

Properties of giant air showers and the problem of estimating the primary-particle energy

The main errors in energy estimation in individual events detected at the Yakutsk EAS array are analyzed. The data on the fraction of muons are considered. For inclined showers with energies exceeding 10¹⁹ eV, it is much larger than the value given by approximation at lower energies. This difference may be due to new processes arising upon interaction between particles with such energies, which leads to a significant increase in the muon component in the total primary-particle energy.     

Changes in the chemical composition of primary cosmic radiation at ultrahigh energies

The signals from particles of extensive air showers in the energy region of 10¹⁷–10²⁰ eV in both the surface and underground scintillation detectors of the Yakutsk array are calculated using the CORSIKA 6.616 and GEANT4 software packages and compared with experimental data. It is shown that a transition from a heavy primary composition to proton primaries at energies (1–2.6) × 10¹⁸ eV and from primary protons again to heavy primaries at energies above 1.3 × 10¹⁹ eV might be observed.     

Radio signals from extensive air showers with the energies <Emphasis Type="Italic">E</Emphasis> <Subscript>0</Subscript> ≥ 10<Superscript>19</Superscript> eV according to data from the Yakutsk extensive air shower array

A radio instrument and results obtained from the measurements of the 32-MHz radio signal from particles of extensive air showers (EASs) with energies E₀ ≥ 1×10¹⁹ eV are reported in brief. The data were obtained at the Yakutsk EAS array in 1987–1989 (the first series of measurements) and in 2009–2014 (new series of measurements). The radio signal from EASs with energies above 10²⁰eV was detected at the Yakutsk EAS array for the first time, including the shower with the record energy of ~2×10²⁰ eV for the Yakutsk EAS array.