Precision Measurement of the Boron to Carbon Flux Ratio in Cosmic Rays from 1.9 GV to 2.6 TV with the Alpha Magnetic Spectrometer on the International Space Station


Creative Commons License

AGUILAR M., CAVASONZA L. A. , AMBROSI G., ARRUDA L., ATTIG N., AUPETIT S., ...More

PHYSICAL REVIEW LETTERS, vol.117, no.23, 2016 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 117 Issue: 23
  • Publication Date: 2016
  • Doi Number: 10.1103/physrevlett.117.231102
  • Title of Journal : PHYSICAL REVIEW LETTERS

Abstract

Knowledge of the rigidity dependence of the boron to carbon flux ratio (B/C) is important in understanding the propagation of cosmic rays. The precise measurement of the B/C ratio from 1.9 GV to 2.6 TV, based on 2.3 million boron and 8.3 million carbon nuclei collected by AMS during the first 5 years of operation, is presented. The detailed variation with rigidity of the B/C spectral index is reported for the first time. The B/C ratio does not show any significant structures in contrast to many cosmic ray models that require such structures at high rigidities. Remarkably, above 65 GV, the B/C ratio is well described by a single power law R. with index. Delta = -0.333 +/- 0.014(fit) +/- 0.005(syst), in good agreement with the Kolmogorov theory of turbulence which predicts. Delta = -1/3 asymptotically.