A1 Refereed original research article in a scientific journal
Properties of Cosmic Helium Isotopes Measured by the Alpha Magnetic Spectrometer
Authors: Aguilar M, Cavasonza LA, Ambrosi G, Arruda L, Attig N, Bachlechner A, Barao F, Barrau A, Barrin L, Bartoloni A, Basegmez-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 MJ, Bourquin M, Bueno EF, Burger J, Burger WJ, Cai XD, Capell M, Caroff S, Casaus J, Castellini G, Cervelli F, Chang YH, Chen GM, Chen HS, Chen Y, Cheng L, Chou HY, Choutko V, Chung CH, Clark C, Coignet G, Consolandi C, Contin A, Corti C, Cui Z, Dadzie K, Dai YM, Datta A, Delgado C, Della Torre S, Demirkoz MB, Derome L, Di Falco S, Di Felice V, Diaz 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, Gamez C, Garcia-Lopez RJ, Gargiulo C, Gast H, Gebauer I, Gervasi M, Giovacchini F, Gomez-Coral DM, Gong J, Goy C, Grabski V, Grandi D, Graziani M, Guo KH, Haino S, Han KC, He ZH, Hsieh TH, Huang H, Huang ZC, Incagli M, Jang WY, Jia Y, Jinchi H, Kanishev K, Khiali B, Kim GN, Kirn T, Konyushikhin M, Kounina O, Kounine A, Koutsenko V, Kulemzin A, La Vacca G, Laudi E, Laurenti G, Lazzizzera I, Lebedev A, Lee HT, Lee SC, Li JQ, Li Q, Li TX, Li ZH, Light C, Lin CH, Lippert T, Liu Z, Lu SQ, Lu YS, Luebelsmeyer K, Luo F, Luo JZ, Luo X, Lyu SS, Machate F, Mana C, Marin J, Martin T, Martinez G, Masi N, Maurin D, Menchaca-Rocha A, Meng Q, Mo DC, Molero M, Mott P, Mussolin L, Nelson T, Ni JQ, Nikonov N, Nozzoli F, Oliva A, Orcinha M, Palermo M, Palmonari F, Paniccia M, Pashnin A, Pauluzzi M, Pensotti S, Phan HD, Plyaskin V, Poireau V, Poluianov S, Popkow A, Qi XM, Qin X, Qu ZY, Quadrani L, Rancoita PG, Rapin D, Conde AR, Rosier-Lees S, Rozhkov A, Rozza D, Sagdeev R, Schael S, Schmidt SM, von Dratzig AS, Schwering G, Seo ES, Shan BS, Shi JY, Siedenburg T, Solano C, Song JW, Sun ZT, Tacconi M, Tang XW, Tang ZC, Tian J, Ting SCC, Ting SM, Tomassetti N, Torsti J, Tuysuz C, Urban T, Usoskin I, Vagelli V, Vainio R, Valente E, Valtonen E, Acosta MV, Vecchi M, Velasco M, Vialle JP, Wang LQ, Wang NH, Wang QL, Wang X, Wang XQ, Wang ZX, Wei J, Weng ZL, Wu H, Xiong RQ, Xu W, Yan Q, Yang Y, Yi H, Yu YJ, Yu ZQ, Zannoni M, Zeissler S, Zhang C, Zhang F, Zhang JH, Zhang Z, Zhao F, Zheng ZM, Zhuang HL, Zhukov V, Zichichi A, Zimmermann N, Zuccon P
Publisher: AMER PHYSICAL SOC
Publication year: 2019
Journal: Physical Review Letters
Journal name in source: PHYSICAL REVIEW LETTERS
Journal acronym: PHYS REV LETT
Article number: ARTN 181102
Volume: 123
Issue: 18
Number of pages: 8
ISSN: 0031-9007
eISSN: 1079-7114
DOI: https://doi.org/10.1103/PhysRevLett.123.181102
Self-archived copy’s web address: https://research.utu.fi/converis/portal/detail/Publication/43848394
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 proportional to R-Delta with Delta = 0.294 0.004. Unexpectedly, this value is in agreement with the B/O and B/C spectral indices at high energies.
Downloadable publication This is an electronic reprint of the original article. |