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The abundances of isotopes in the cosmic radiation

1989; American Institute of Physics; Linguagem: Inglês

10.1063/1.38009

1935-0465

R. A. Mewaldt,

Astrophysics and Cosmic Phenomena

Studies of the isotopic composition of nuclei in the cosmic radiation are reviewed, including abundances of the isotopes of elements from H to Ni (nuclear charge 1<Z<28), and their implications for cosmic ray origin, acceleration, and transport in the Galaxy. The review focuses on determinations of the composition of cosmic ray source material, and the extent to which the isotopic composition of this material is different from, or similar to, typical solar system material and other samples of Galactic matter. Theoretical models that have been advanced to explain the observed overabundance of neutron‐rich isotopes in cosmic rays are described. Also discussed are studies of various radioactive ‘‘clocks’’ that record the time‐scales associated with the nucleosynthesis, acceleration, and transport of cosmic ray nuclei, and studies of the so‐called ‘‘anomalous’’ cosmic ray component, thought to represent a sample of the neutral interstellar medium. Finally, the goals and prospects for future cosmic ray isotope spectrometers are described.