BEXCO - Room A(101/102)
[CRD062] Precision Measurement of the Boron-to-Carbon Flux Ratio in Cosmic Rays with the Alpha Magnetic Spectrometer on the ISS
Knowledge of the rigidity dependence of the boron-to-carbon flux ratio (B/C) is important in understanding the propagation of cosmic rays. A precise measurement of the B/C ratio in cosmic rays with rigidity from 1.9 GV to 2.6 TV, based on 2.3 million boron nuclei and 8.3 million carbon nuclei collected by AMS during the first 5 years of operation, is presented. 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^γ with index γ=−0.333±0.014(fit)±0.005(syst), in good agreement with the Kolmogorov theory of turbulence which predicts γ=−1/3 asymptotically.