INFN and U. of Perugia, Italy
A Solution of the Knee and Ankle Problem in the Cosmic Ray Spectrum
The differential energy spectrum of the cosmic rays presents two deviations (the knee and the ankle) with respect to a constant spectral index of 2.7 at energies above 1015 eV (knee) and 5 x 1018 eV (ankle). A new mechanism accounting for both deviations is presented. The mechanism is based on observational data regarding the size and the magnetic field in the Galaxy and assumes constant spectral indices of individual ions of the cosmic radiation from 10 GeV up to 6 x 1019 eV. The excellent agreement, spanning 5 energy decades, with the measured spectra of the cosmic radiation is discussed and highlighted.