We present new measurements of the energy spectra of cosmic-ray (CR) nuclei from the second flight of the balloon-borne experiment CREAM (Cosmic Ray Energetics And Mass). The instrument (CREAM-II) was comprised of detectors based on different techniques (Cherenkov light, specific ionization in scintillators and silicon sensors) to provide a redundant charge identification and a thin ionization calorimeter capable of measuring the energy of cosmic rays up to several hundreds of TeV. The data analysis is described and the individual energy spectra of C, O, Ne, Mg, Si and Fe are reported up to ~ 10^14 eV. The spectral shape looks nearly the same for all the primary elements and can be expressed as a power law in energy E^{-2.66+/-0.04}. The nitrogen absolute intensity in the energy range 100-800 GeV/n is also measured.
@article{arxiv.1003.5759,
title = {Elemental energy spectra of cosmic rays measured by CREAM-II},
author = {P. Maestro and H. S. Ahn and P. Allison and M. G. Bagliesi and L. Barbier and J. J. Beatty and G. Bigongiari and T. J. Brandt and J. T. Childers and N. B. Conklin and S. Coutu and M. A. DuVernois and O. Ganel and J. H. Han and J. A. Jeon and K. C. Kim and M. H. Lee and A. Malinine and P. S. Marrocchesi and S. Minnick and S. I. Mognet and S. W. Nam and S. Nutter and I. H. Park and N. H. Park and E. S. Seo and R. Sina and P. Walpole and J. Wu and J. Yang and Y. S. Yoon and R. Zei and S. Y. Zinn},
journal= {arXiv preprint arXiv:1003.5759},
year = {2010}
}
Comments
4 pages, 3 figures, presented at ICRC 2009, Lodz, Poland