Mass Composition of Primary Cosmic Ray below the 'Knee' Deduced from Analysis of Energy Distribution of Hadrons Registered in the Pamir Experiment

摘要

Energy spectra of hadrons registered in carbon emulsion chambers have been obtained from the Pamir experimental data.Calculations simulating propagation of primary cosmic ray particles through the atmosphere to the mountain level have been done with the use of the CORSIKA program with QGSJET model.Comparison of the experimental data with the calculated spectra enables to state that primary cosmic ray for energies from 10~(13) eV up to 5centre dot10~(15) eV have light mass composition.In the energy interval above 10~(15) eV primary cosmic ray have the following mass composition:over 50% of light nuclei (about 30% p and over 20% He) and about 14% Fe.Average logarithm of mass number < lnA > varies from 1.57 for E_0=10~(13) eV up to 1.85 for E_0=5centre dot10~(15) eV.