The isotopic composition of galactic cosmic-ray iron nuclei
Abstract
High-resolution observations made in interplanetary space of 83-284 MeV per nucleon galactic cosmic-ray iron isotopes are reported and it is directly established that Fe-56 is the dominant cosmic-ray Fe isotope. The following percentage abundances for Fe at the cosmic-ray source are found: Fe-54 = 9(+8, -5)%, Fe-55 is less than or equal to 7%, Fe-56 = 91(+5, -11)%, Fe-57 is less than or equal to 8%, and Fe-58 is less than or equal to 6%. When compared to calculated nucleosynthesis yields and other observations, these results place significant constraints on the neutron excess of the environment where cosmic-ray Fe originates.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 1980
- DOI:
- 10.1086/183211
- Bibcode:
- 1980ApJ...236L.121M
- Keywords:
-
- Abundance;
- Cosmic Rays;
- Galactic Radiation;
- Iron Isotopes;
- Nuclear Fusion;
- Nuclei (Nuclear Physics);
- International Sun Earth Explorer 3;
- Iron 57;
- Mass Ratios;
- Space Radiation