The propagation of cosmic ray nuclei slightly heavier than iron

The corrections for the effects introduce by propagation on the source abundances of cosmic ray nuclei have been re-evaluated for those nuclei a little heavier than iron, 28 < Z < 40. The lighter of these nuclei have cosmic abundances that decrease rapidly with increasing charge and hence their abundances should be less sensitive than in general to the production of fragments of heavier nuclei. This re-evaluation is based on a leaky box model and uses the latest cross sections of Silberberg and Tsao. Full allowance has been made for the effects of radioactive decays and for the suppression of K-captures at cosmic ray energies. Particular attention has been paid to a study of the effects of varying the assumed cross sections. Since several of the elements in this charge range are of interest in attempting to distinguish between rival theories of the origin these will be considered in some detail.