PROPAGATION AND SOURCE ENERGY SPECTRA OF COSMIC RAY NUCLEI AT HIGH ENERGIES
A recent measurement of the TRACER instrument on long-duration balloon has determined the individual energy spectra of the major primary cosmic ray nuclei from oxygen (Z = 8) to iron (Z = 26). The measurements cover a large range of energies and extend to energies beyond 10{sup 14} eV. We investigate if the data set can be described by a simple but plausible model for acceleration and propagation of cosmic rays. The model assumes a power-law energy spectrum at the source with a common spectral index {alpha} for all nuclear species, and an energy-dependent propagation path length ({lambda} {proportional_to} E {sup -0.6}) combined with an energy-independent residual path length {lambda}{sub 0}. We find that the data can be fitted with a fairly soft source spectrum ({alpha} = 2.3-2.4), and with a residual path length {lambda}{sub 0} as high as 0.3 g cm{sup -2}. We discuss this model in the context of other pertinent information, and we determine the relative abundances of the elements at the cosmic ray source.
- OSTI ID:
- 21300591
- Journal Information:
- Astrophysical Journal, Vol. 697, Issue 1; Other Information: DOI: 10.1088/0004-637X/697/1/106; Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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