The energy spectrum of cosmic rays with primary energies between 1014 eV and 1016 eV has been studied with the CASA-MIA air shower array. The measured differential energy spectrum is a power law (dj/dE ∝ E-γ) with spectral indices γ of 2.66 ± 0.02 below approximately 1015 eV and 3.00 ± 0.05 above. A new method is used for measuring primary energy derived from ground-based data in a compositionally insensitive way. In contrast with some previous reports, the "knee" of the energy spectrum does not appear sharp, but rather a smooth transition over energies from 1015 eV to 3.0 × 1015 eV.
|Original language||English (US)|
|Number of pages||12|
|State||Published - May 1999|