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arXiv · 1908.01508

Mass composition of cosmic rays above 0.1 EeV by the Yakutsk array data

Stanislav Knurenko·Igor Petrov
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Abstract

The paper presents the results of the longitudinal development of extensive air showers (X$_{max}$) of ultra-high energies and mass composition of cosmic rays. The measurements of X$_{max}$ are based on data from observations of the Cherenkov radiation at the Yakutsk array for the period 1974-2014. The cascade curves of individual showers and the depth of maximum X$_{max}$ were reconstructed over the energy range 10$^{16}$-5.7$\cdot$10$^{19}$ eV. It is shown that the displacement rate of the parameter dX$_{max}$ / dE in the atmosphere is nonlinear and depends on the energy. Such a feature indicates a change in mass composition, which is confirmed by fluctuations of X$_{max}$ in this energy region. The composition of cosmic rays was determined by interpolation using the QGSJetII-04 model.

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Stanislav Knurenko, Igor Petrov. 2019-08-05. Mass composition of cosmic rays above 0.1 EeV by the Yakutsk array data. https://doi.org/10.1016/j.asr.2019.07.019

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