Aguilar, M.M.AguilarAli Cavasonza, L.L.Ali CavasonzaAmbrosi, G.G.AmbrosiBertucci, B.B.BertucciD'Urso, DomenicoDomenicoD'UrsoNozzoli, FrancescoFrancescoNozzoliOliva, A.A.OlivaPizzolotto, CeciliaCeciliaPizzolottoVitale, VincenzoVincenzoVitale2020-09-172020-09-172016-12-01https://hdl.handle.net/20.500.13025/4893Physical Review Letters, Volume 117, Issue 23, id.231102Knowledge 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<SUP>Delta</SUP> 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.10.1103/PhysRevLett.117.231102http://adsabs.harvard.edu/abs/2016PhRvL.117w1102A2016PhRvL.117w1102A