Cosmic Ray Anisotropy and the Knee of the Energy Spectrum

Abstract

The knee of the cosmic:ray energy spectrum occurs at an energy slightly below 101 6 eV. At a similar energy significant changes are found in cosmic ray shower development and anisotropy. It is suggested that these changes can be understood if there is a general proton dominated cosmic ray flux along our spiral arm from outer galactic regions, which is exceeded by an iron dominated flux from the opposite spiral arm direction at energies between ~ 1014 and ~ 101 7 eV.