English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The energy spectrum of the primary cosmic radiation in the energy range 1 -100 PeV and the extensive air shower (EAS) characteristics obtained on thebasis of the expanded data bank of the GAMMA experiment (Mt. Aragats, Armenia)are presented. With increased statistics we confirm our previous results on theenergy spectrum. The spectral index above the knee is about -3.1, but atenergies beyond 20 PeV a flattening of the spectrum is observed. The existenceof the 'bump' at about 70 PeV is confirmed with a significance of more than4{\sigma}. In the energy range of 10 - 100 PeV the shower age becomes energyindependent and we observe a direct proportionality of the EAS size to theprimary energy. This suggests an approximately constant depth of the EASmaximum in this energy range. This is evidence in favour of an increasingaverage mass of primary particles at energies above 20 PeV. The additionalsource scenario, which is a possible explanation of the 'bump' in the spectrum,also leads to the conclusion of increasing mass of the primary cosmic rays. Acomparison with the data of other experiments is presented.

Energy spectrum and mass composition of primary cosmic radiation in the region above the knee from the GAMMA experiment