Structures in the cosmic ray energy spectra

All the components of Cosmic Rays (CR) have ‘structure’ in their energy spectra at some level, i.e. deviations from a simple power law, and their examination is relevant to the origin of the particles. Emphasis, here, is placed on the large-scale structures in the spectra of nuclei (the ‘knee’ at about 3 PeV), that of electrons plus positrons (a shallow ‘upturn’ at about 100 GeV) and the positron to electron plus positron ratio (an upturn starting at about 5 GeV).Fine structure is defined as deviations from the smooth spectra which already allow for the large-scale structure. Search for the fine structure has been performed in the precise data on positron to electron plus positron ratio measured by the AMS-02 experiment. Although no fine structure is indicated, it could in fact be present at the few percent level.