The Effect of Cross-Section Uncertainties on the Derivation of Source Abundances from Cosmic-Ray Composition Observations
The abundance of a cosmic-ray nuclide observed near Earth is composed of two parts which we designate as ‘primary’ and ‘secondary’. The primary particles are those which were accelerated at the cosmic-ray ‘source’ and have survived their traversal of the interstellar medium without undergoing a nuclear interaction which would change their identity (i. e., either their number of protons or their number of neutrons). The secondary particles are the fragments produced in the break-up of heavier nuclides which have undergone destructive collisions with atoms in the interstellar gas. The derivation of source abundances from the composition observed near Earth requires that the secondary contribution to the observed nuclidic abundances be calculated from a model of cosmic-ray propagation.
Unable to display preview. Download preview PDF.
- 3.Reames, D.V.: 1974, in “High Energy Particles and Quanta in Astrophysics,” eds. F.B. McDonald and C.E. Fichtel ( Cambridge: MIT Press ), pp. 54–121.Google Scholar