Author/Authors :
M.E. Wiedenbeck، نويسنده , , W.R. Binns، نويسنده , , E.R. Christian، نويسنده , , A.C. Cummings، نويسنده , , A.J. Davis، نويسنده , , J.S. George، نويسنده , , P.L. Hink، نويسنده , , M.H. Israel، نويسنده , , R.A. Leske، نويسنده , , M. Lijowski، نويسنده , , R.A Mewaldt، نويسنده , , E.C. Stone، نويسنده , , T.T. von Rosenvinge، نويسنده , , N.E. Yanasak، نويسنده ,
Abstract :
The isotopic composition of cosmic-ray Fe, Co, and Ni at energies ∼150–500 MeV/nucleon has been measured with the Cosmic-Ray Isotope Spectrometer (CRIS) instrument on ACE. Source abundances have been derived from a leaky-box propagation model using secondary species in the range 41 ≤ A ≤ 55 to constrain the calculated secondary contributions to the Fe, Co, and Ni isotopes. The derived relative source abundances bear a strong resemblance to solar-system values. The most significant difference, an excess of ∼ (70 ± 30)%, is found for the source abundance ratio 58Fe/56Fe. Some implications of the derived source composition for the origin of cosmic rays are discussed.
