Nuclear Composition and Energy Spectra in the 1969 April 12 Solar-Particle Event
Abstract
The charge composition for several of the multicharged nuclei and the energy spectra for hydrogen, helium, and medium (6 < Z < 9) nuclei were measured in the 1969 April 12 solar-particle event. The energy/nucleon shape of the medium nuclei was again the same as that of the helium nuclei, and the ratio of these two species was consistent with the present best average of 58 * 5. By combining the results obtained here with previous work, improved estimates of the Ne/O and Mg/O values of 0.16 * 0.03 and 0.056 i 0.014, respectively, were obtained. Silicon and sulfur abundances relative to 0 were determined to be 0.208 i 0.010 and 0.008 i 0.006, respectively, and 85 percent confidence upper limits for Ar and Ca relative to 0 of 0.017 and 0.010 were obtained. Previously, these last four nuclei had only been listed as a group.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- January 1972
- DOI:
- 10.1086/151268
- Bibcode:
- 1972ApJ...171..169B