Source composition of cosmic rays

A theory is developed that yields great improvement in deriving the cosmic‐ray source abundances for energies below 1012 eV/u. In addition, based on the acceleration theory of Volk and Biermann and on nucleosynthesis processes in pre‐supernova stars, a theory is presented for the source composition at 1012–1015 eV/u. The strong shock wave of young supernova remnant accelerates the wind particles of the pre‐supernova red, blue supergiant stars and Wolf‐Rayet (WR) stars to energies up to 1015 eV/u. They contain the nucleosynthesis products of the CNO cycle and of He‐burning. They accelerate the flare particles in interstellar space. The composition below 1012 eV/u differs from that of the general stellar photosphere by: (1) Suppression of elements with a large FIP (≳10 eV) by a factor of 4; (2) The depletion of light nuclei (Z≤10); (3) A large contribution of WC stars to 12C, 16O and 22Ne, with renormalization of the initial (Z≳2)/(Z≤2) abundances of Prantzos et al., based on general elemental abundances.