123287657
Energy spectra and elemental composition determination on mountain altitudes and sea level
The accurate measurement of the elemental composition and energy spectra of primary cosmic rays in the energy range 10 14 – 10 17 eV is vitally important. The information carried by Extensive Air showers (EAS) in this energy range is limited by significant fluctuations of the shower development, insufficient experimental sampling and uncertainties of the detector response. Additional uncertainties arise from different simulation procedures and statistical methods used for inferring results from the measurements. We propose to combine an advanced EAS simulation program like CORSIKA with the ANI multivariate statistical analysis package for an event-by-event analysis and for a standardization of the inference from EAS data. As an example, the possibilities of modern EAS installations at mountain altitudes and sea level are explored. The accuracies of the elemental composition determination based on measured components of EAS are presented. The Neural Networks classification and Bayesian Decision Making approaches are used and compared. The new nonparametric methods of primary energy estimations are discussed.
14618248
Anisotropy analysis of EAS data in the knee region
Based on MAKET-ANI EAS data the distributions of equatorial coordinates of EAS core directions are obtained in the knee region. Anisotropy of primary cosmic rays is displayed only by declination equatorial coordinates (20+/-3 degrees) at primary energies more than 5-10 PeV. The fraction of anisotropic component turns out ~10% in the knee region.
14850539
About EAS inverse approach
It is shown that using the observed extensive air shower (EAS) electron and truncated muon size spectra at sea level one can solve the EAS inverse problem - reconstruction of primary energy spectra and elemental composition, for not more than 2 kinds of primary nuclei.
67805728
Results from the GAMMA experiment on Mt. Aragats
The present status of the GAMMA facility consisting of an enlarged surface EAS array (116 of 1 m^2 scintillation detectors) and underground muon carpet (150 m^2 detectors) is described. The recent results on mass composition and energy spectrum at the energy region above the knee obtained on the basis of the GAMMA experimental data are presented. It is shown that the power law after the knee is not invariable like -3.1. The slope of the energy spectrum becomes more flat at E0>20 PeV. The strong irregularities of the energy spectrum at about 70-80 PeV are discussed in comparison with other experiments. The bump can be described by a two-component model of primary cosmic ray origin, where additional (pulsar) Fe components are included with a very flat power law energy spectrum.
103336904
Calibration of energy measured in Roentgen emulsion experiments. (In Russian)
125873936
A Program for investigation of the muon component in EAS on the magnetic spectrometer ANI in the energy range from 5-GeV to 3000-GeV
15964309
Mutually compensative pseudo solutions of primary energy spectra in the knee region
Abstract The problem of the uniqueness of solutions during the evaluation of primary energy spectra in the knee region using an extensive air shower (EAS) data set and the EAS inverse approach is investigated. It is shown that the unfolding of primary energy spectra in the knee region leads to mutually compensative pseudo solutions. These solutions may be the reason for the observed disagreements in the elementary energy spectra of cosmic rays in the 1–100 PeV energy range obtained from different experiments.
118825755
Alternative description of particle shower longitudinal profile
An alternative parametrization of the particle shower longitudinal profile is presented. The accuracy of the obtained shower profile description is about 2-3% for the 0-1500 g/cm^2 atmosphere slant depths and primary H, He,... Fe nuclei in the 1 PeV-10 EeV energy range. It is shown that the shape of shower profile depends only on the nucleon energy, whereas the maximum shower size also depends on the energy of the parental nucleus. Results are based on the CORSIKA simulated shower profiles and are presented in comparison with the Gaisser-Hillas parametrization.
118956991
Primary Energy Spectra and Elemental Composition. GAMMA Experiment
On the basis of the Extensive Air Shower data observed by the GAMMA experiment the energy spectra and elemental composition of the primary cosmic rays have been derived in the 1-100 PeV energy range. Reconstruction of the primary energy spectra is carried out in the framework of the SIBYLL and QGSJET interaction models and the hypothesis of the power-law steepening primary energy spectra. All presented results are derived taking into account the detector response, reconstruction uncertainties of EAS parameters and fluctuation of EAS development.