High-resolution observations of the isotopic composition of carbon and silicon in the galactic cosmic rays

Journal Article · Sat Aug 01 04:00:00 EDT 1981 · Astrophys. J., Lett. Ed.; (United States)

DOI:https://doi.org/10.1086/183603· OSTI ID:5979598

Wiedenbeck, M E; Greiner, D E

High-resolution (sigma/sub M/<0.25 amu) satellite observations of the galactic cosmic rays (approx.100--300 MeV amu/sup -1/) have yielded determinations of near-Earth isotopic composition as follows: /sup 13/C//sup 12/C = 0.070 +- 0.006; /sup 29/Si//sup 28/Si = 0.109(+0.024, -0.014); and /sup 30/Si//sup 28/Si = 0.084(+0.020, -0.014). Employing a standard propagation model, source values greater than solar are derived for each of these ratios. The /sup 13/C excess may be the result of cross section uncertainties, but the /sup 29/Si and /sup 30/Si appear to reflect real differences between the galactic cosmic-ray source and the solar system.

• Research Organization: Space Sciences Laboratory; University of California, Berkeley
• OSTI ID: 5979598
• Journal Information: Astrophys. J., Lett. Ed.; (United States), Journal Name: Astrophys. J., Lett. Ed.; (United States) Vol. 247:3; ISSN AJLEA
• Country of Publication: United States
• Language: English

Related Subjects

640101* -- Astrophysics &amp; Cosmology-- Cosmic Radiation
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABUNDANCE
CARBON 12
CARBON 13
CARBON ISOTOPES
CHEMICAL COMPOSITION
CHEMISTRY
COSMIC RADIATION
COSMIC RAY PROPAGATION
COSMIC RAY SOURCES
COSMOCHEMISTRY
CROSS SECTIONS
DATA
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
EXPERIMENTAL DATA
FRAGMENTATION
GALAXIES
INFORMATION
IONIZING RADIATIONS
ISOTOPE RATIO
ISOTOPES
LIGHT NUCLEI
MILKY WAY
NUCLEI
NUMERICAL DATA
RADIATIONS
SILICON ISOTOPES
SOLAR SYSTEM
STABLE ISOTOPES