Production of Low-Energy (0.1-10-MeV) Positrons in the Cosmic Radiation

It is shown that a large flux of positrons with energies below 10 MeV will be introduced into the cos- mic radiation by the j9-decay of certain isotopes of carbon, nitrogen, and oxygen produced in interac- tions of cosmic rays with interstellar hydrogen. Fluxes and energy spectra of the positrons are estimated to within an order of magnitude. The significance of this fl-decay origin of cosmic-ray positrons is dis- cussed