The Heavy Nuclei of the Primary Cosmic Radiation

The flux of primary cosmic-ray nuclei, heavier than protons, was determined at geomagnetic latitudes =55^ and =30^ ^. It is shown that at =30^ at least one-half of the incident nucleons and a significant fraction of the incident cosmic-ray energy is due to the heavy component. The distribution of atomic numbers among the primaries was determined at both latitudes; the relative magnitude of the fluxes of the nuclei H: He: C, N, O: (nuclei of charge Z>10 is given approximately by the ratio 4000: 1000: 35: 10. The possible significance of these results for the theories on the origin of cosmic rays is discussed.