@article{46d7c58f1cdf42c3a6db26c186cee81f,
title = "Properties of Cosmic Helium Isotopes Measured by the Alpha Magnetic Spectrometer",
abstract = "Precision measurements by the Alpha Magnetic Spectrometer (AMS) on the International Space Station of He3 and He4 fluxes are presented. The measurements are based on 100 million He4 nuclei in the rigidity range from 2.1 to 21 GV and 18 million He3 from 1.9 to 15 GV collected from May 2011 to November 2017. We observed that the He3 and He4 fluxes exhibit nearly identical variations with time. The relative magnitude of the variations decreases with increasing rigidity. The rigidity dependence of the He3/He4 flux ratio is measured for the first time. Below 4 GV, the He3/He4 flux ratio was found to have a significant long-term time dependence. Above 4 GV, the He3/He4 flux ratio was found to be time independent, and its rigidity dependence is well described by a single power law ∈RΔ with Δ=-0.294±0.004. Unexpectedly, this value is in agreement with the B/O and B/C spectral indices at high energies.",
author = "{AMS Collaboration} and M. Aguilar and {Ali Cavasonza}, L. and G. Ambrosi and L. Arruda and N. Attig and A. Bachlechner and F. Barao and A. Barrau and L. Barrin and A. Bartoloni and {Ba{\c s}eǧmez-Du Pree}, S. and R. Battiston and U. Becker and M. Behlmann and B. Beischer and J. Berdugo and B. Bertucci and V. Bindi and {De Boer}, W. and K. Bollweg and B. Borgia and Boschini, {M. J.} and M. Bourquin and Bueno, {E. F.} and J. Burger and Burger, {W. J.} and Cai, {X. D.} and M. Capell and S. Caroff and J. Casaus and G. Castellini and F. Cervelli and Chang, {Y. H.} and Chen, {G. M.} and Chen, {H. S.} and Y. Chen and L. Cheng and Chou, {H. Y.} and V. Choutko and Chung, {C. H.} and C. Clark and G. Coignet and C. Consolandi and A. Contin and C. Corti and Z. Cui and K. Dadzie and Dai, {Y. M.} and A. Datta and C. Delgado",
note = "Publisher Copyright: {\textcopyright} 2019 authors. Published by the American Physical Society.",
year = "2019",
month = nov,
day = "1",
doi = "10.1103/PhysRevLett.123.181102",
language = "???core.languages.en_GB???",
volume = "123",
journal = "Physical Review Letters",
issn = "0031-9007",
number = "18",
}