Cosmic rays: material from coronae of ordinary stars and from He-burning zones, but not from s-process sites.

The galactic cosmic ray (GCR) composition seems to tell us that the bulk of the GCR nuclei were first extracted out of the coronae of ordinary F to M stars. They were most likely first accelerated to MeV energies by stellar flares, and later on boosted up to GeV energies by SNR (and possibly massive star wind) shocks. A small fraction of them (≡2%) should originate in He-burning material, plausibly in Wolf-Rayet stars.