Study of the energy spectrum and mass composition of primary cosmic rays in the energy range of 1018–1020 eV using a balloon setup in antarctica (SPHERE-antarctica project)

An Antarctic balloon experiment for measuring the energy spectrum and elemental composition of cosmic rays in the ultrahigh-energy range (1018–1020) eV is proposed. Scientific equipment will measure fluorescence caused by an extensive air shower formed in the atmosphere by an ultrahigh energy particle and Cherenkov light of this shower reflected from a snow surface. It is assumed that the balloon will fly in the circumpolar orbit in Antarctica at a height of ~25 km for (2–3) winter (in the Southern Hemisphere)months. For this time, ~3000 events caused by particles with energies above 1018 eV and (200–300) events caused by particles with energies above 1019 eV will be detected.