Bibcode
Aguilar, M.; Ali Cavasonza, L.; Ambrosi, G.; Arruda, L.; Attig, N.; Bachlechner, A.; Barao, F.; Barrau, A.; Barrin, L.; Bartoloni, A.; Bașeǧmez-du Pree, S.; Battiston, R.; Becker, U.; Behlmann, M.; Beischer, B.; Berdugo, J.; Bertucci, B.; Bindi, V.; de Boer, W.; Bollweg, K.; Borgia, B.; Boschini, M. J.; Bourquin, M.; Bueno, E. F.; Burger, J.; Burger, W. J.; Cai, X. D.; Capell, M.; Caroff, S.; Casaus, J.; Castellini, G.; Cervelli, F.; Chang, Y. H.; Chen, G. M.; Chen, H. S.; Chen, Y.; Cheng, L.; Chou, H. Y.; Choutko, V.; Chung, C. H.; Clark, C.; Coignet, G.; Consolandi, C.; Contin, A.; Corti, C.; Cui, Z.; Dadzie, K.; Dai, Y. M.; Datta, A.; Delgado, C.; Della Torre, S.; Demirköz, M. B.; Derome, L.; Di Falco, S.; Di Felice, V.; Díaz, C.; Dimiccoli, F.; von Doetinchem, P.; Dong, F.; Donnini, F.; Duranti, M.; Egorov, A.; Eline, A.; Feng, J.; Fiandrini, E.; Fisher, P.; Formato, V.; Galaktionov, Y.; Gámez, C.; García-López, R. J.; Gargiulo, C.; Gast, H.; Gebauer, I.; Gervasi, M.; Giovacchini, F.; Gómez-Coral, D. M.; Gong, J.; Goy, C.; Grabski, V.; Grandi, D.; Graziani, M.; Guo, K. H.; Haino, S.; Han, K. C.; He, Z. H.; Hsieh, T. H.; Huang, H.; Huang, Z. C.; Incagli, M.; Jang, W. Y.; Jia, Yi; Jinchi, H.; Kanishev, K.; Khiali, B.; Kim, G. N.; Kirn, Th.; Konyushikhin, M.; Kounina, O.; Kounine, A.; Koutsenko, V. et al.
Bibliographical reference
Physical Review Letters
Advertised on:
11
2019
Journal
Citations
47
Refereed citations
43
Description
Precision measurements by the Alpha Magnetic Spectrometer (AMS) on the International Space Station of He 3 and He 4 fluxes are presented. The measurements are based on 100 million He 4 nuclei in the rigidity range from 2.1 to 21 GV and 18 million He 3 from 1.9 to 15 GV collected from May 2011 to November 2017. We observed that the He 3 and He 4 fluxes exhibit nearly identical variations with time. The relative magnitude of the variations decreases with increasing rigidity. The rigidity dependence of the He 3 /He 4 flux ratio is measured for the first time. Below 4 GV, the He 3 /He 4 flux ratio was found to have a significant long-term time dependence. Above 4 GV, the He 3 /He 4 flux ratio was found to be time independent, and its rigidity dependence is well described by a single power law ∝R∆ with ∆ =-0.294 ±0.004 . Unexpectedly, this value is in agreement with the B/O and B/C spectral indices at high energies.
Related projects
Particle Astrophysics
The members of the Particle Astrophysics Group of the IAC participate actively in three large international collaborations of high-energy astrophysics: AMS-02 (Alpha Magnetic Spectrometer), the Cherenkov radiation telescopes MAGIC I and II and the Cherenkov Telescope Array Observatory ( CTAO). We also participate in the ASTRI mini-array, the gamma
Mónica Luisa
Vázquez Acosta