Precision Measurement of the Helium Flux in Primary Cosmic Rays of Rigidities 1.9 GV to 3 TV with the Alpha Magnetic Spectrometer on the International Space Station

M. Aguilar, D. Aisa, B. Alpat, A. Alvino, G. Ambrosi, K. Andeen, L. Arruda, N. Attig, P. Azzarello, A. Bachlechner, F. Barao, A. Barrau, L. Barrin, A. Bartoloni, L. Basara, M. Battarbee, R. Battiston, J. Bazo, U. Becker, M. BehlmannB. Beischer, J. Berdugo, B. Bertucci, V. Bindi, S. Bizzaglia, M. Bizzarri, G. Boella, W. De Boer, K. Bollweg, V. Bonnivard, B. Borgia, S. Borsini, M. J. Boschini, M. Bourquin, J. Burger, F. Cadoux, X. D. Cai, M. Capell, S. Caroff, J. Casaus, G. Castellini, I. Cernuda, D. Cerreta, F. Cervelli, M. J. Chae, Y. H. Chang, A. I. Chen, G. M. Chen, H. Chen, H. S. Chen, L. Cheng, H. Y. Chou, E. Choumilov, V. Choutko, C. H. Chung, C. Clark, R. Clavero, G. Coignet, C. Consolandi, A. Contin, C. Corti, E. Cortina Gil, B. Coste, W. Creus, M. Crispoltoni, Z. Cui, Y. M. Dai, C. Delgado, S. Della Torre, M. B. Demirköz, L. Derome, S. Di Falco, L. Di Masso, F. Dimiccoli, C. Díaz, P. Von Doetinchem, F. Donnini, M. Duranti, D. D'urso, A. Egorov, A. Eline, F. J. Eppling, T. Eronen, Y. Y. Fan, L. Farnesini, J. Feng, E. Fiandrini, A. Fiasson, E. Finch, P. Fisher, V. Formato, Y. Galaktionov, G. Gallucci, B. García, R. García-López, C. Gargiulo, H. Gast, I. Gebauer, M. Gervasi, A. Ghelfi, F. Giovacchini, P. Goglov, J. Gong, C. Goy, V. Grabski, D. Grandi, M. Graziani, C. Guandalini, I. Guerri, K. H. Guo, D. Haas, M. Habiby, S. Haino, K. C. Han, Z. H. He, M. Heil, J. Hoffman, T. H. Hsieh, Z. C. Huang, C. Huh, M. Incagli, M. Ionica, W. Y. Jang, H. Jinchi, K. Kanishev, G. N. Kim, K. S. Kim, Th Kirn, M. A. Korkmaz, R. Kossakowski, O. Kounina, A. Kounine, V. Koutsenko, M. S. Krafczyk, G. La Vacca, E. Laudi, G. Laurenti, I. Lazzizzera, A. Lebedev, H. T. Lee, S. C. Lee, C. Leluc, H. L. Li, J. Q. Li, J. Q. Li, Q. Li, Q. Li, T. X. Li, W. Li, Y. Li, Z. H. Li, Z. Y. Li, S. Lim, C. H. Lin, P. Lipari, T. Lippert, D. Liu, H. Liu, Hu Liu, M. Lolli, T. Lomtadze, M. J. Lu, S. Q. Lu, Y. S. Lu, K. Luebelsmeyer, F. Luo, J. Z. Luo, S. S. Lv, R. Majka, C. Mañá, J. Marín, T. Martin, G. Martínez, N. Masi, D. Maurin, A. Menchaca-Rocha, Q. Meng, D. C. Mo, L. Morescalchi, P. Mott, M. Müller, T. Nelson, J. Q. Ni, N. Nikonov, F. Nozzoli, P. Nunes, A. Obermeier, A. Oliva, M. Orcinha, F. Palmonari, C. Palomares, M. Paniccia, A. Papi, M. Pauluzzi, E. Pedreschi, S. Pensotti, R. Pereira, N. Picot-Clemente, F. Pilo, A. Piluso, C. Pizzolotto, V. Plyaskin, M. Pohl, V. Poireau, A. Putze, L. Quadrani, X. M. Qi, X. Qin, Z. Y. Qu, T. Räihä, P. G. Rancoita, D. Rapin, J. S. Ricol, I. Rodríguez, S. Rosier-Lees, A. Rozhkov, D. Rozza, R. Sagdeev, J. Sandweiss, P. Saouter, S. Schael, S. M. Schmidt, A. Schulz Von Dratzig, G. Schwering, G. Scolieri, E. S. Seo, B. S. Shan, Y. H. Shan, J. Y. Shi, X. Y. Shi, Y. M. Shi, T. Siedenburg, D. Son, J. W. Song, F. Spada, F. Spinella, W. Sun, W. H. Sun, M. Tacconi, C. P. Tang, X. W. Tang, Z. C. Tang, L. Tao, D. Tescaro, Samuel C C Ting, S. M. Ting, N. Tomassetti, J. Torsti, C. Türkoʇlu, T. Urban, V. Vagelli, E. Valente, C. Vannini, E. Valtonen, S. Vaurynovich, M. Vecchi, M. Velasco, J. P. Vialle, V. Vitale, S. Vitillo, L. Q. Wang, N. H. Wang, Q. L. Wang, R. S. Wang, X. Wang, Z. X. Wang, Z. L. Weng, K. Whitman, J. Wienkenhöver, M. Willenbrock, H. Wu, X. Wu, X. Xia, M. Xie, S. Xie, R. Q. Xiong, N. S. Xu, W. Xu, Q. Yan, J. Yang, M. Yang, Y. Yang, Q. H. Ye, H. Yi, Y. J. Yu, Z. Q. Yu, S. Zeissler, C. Zhang, J. H. Zhang, M. T. Zhang, S. D. Zhang, S. W. Zhang, X. B. Zhang, Z. Zhang, Z. M. Zheng, H. L. Zhuang, V. Zhukov, A. Zichichi, N. Zimmermann, P. Zuccon

Research output: Contribution to journalArticle

300 Scopus citations

Abstract

Knowledge of the precise rigidity dependence of the helium flux is important in understanding the origin, acceleration, and propagation of cosmic rays. A precise measurement of the helium flux in primary cosmic rays with rigidity (momentum/charge) from 1.9 GV to 3 TV based on 50 million events is presented and compared to the proton flux. The detailed variation with rigidity of the helium flux spectral index is presented for the first time. The spectral index progressively hardens at rigidities larger than 100 GV. The rigidity dependence of the helium flux spectral index is similar to that of the proton spectral index though the magnitudes are different. Remarkably, the spectral index of the proton to helium flux ratio increases with rigidity up to 45 GV and then becomes constant; the flux ratio above 45 GV is well described by a single power law.

Original languageEnglish (US)
Article number211101
JournalPhysical Review Letters
Volume115
Issue number21
DOIs
StatePublished - Nov 17 2015

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Fingerprint Dive into the research topics of 'Precision Measurement of the Helium Flux in Primary Cosmic Rays of Rigidities 1.9 GV to 3 TV with the Alpha Magnetic Spectrometer on the International Space Station'. Together they form a unique fingerprint.

  • Cite this

    Aguilar, M., Aisa, D., Alpat, B., Alvino, A., Ambrosi, G., Andeen, K., Arruda, L., Attig, N., Azzarello, P., Bachlechner, A., Barao, F., Barrau, A., Barrin, L., Bartoloni, A., Basara, L., Battarbee, M., Battiston, R., Bazo, J., Becker, U., ... Zuccon, P. (2015). Precision Measurement of the Helium Flux in Primary Cosmic Rays of Rigidities 1.9 GV to 3 TV with the Alpha Magnetic Spectrometer on the International Space Station. Physical Review Letters, 115(21), [211101]. https://doi.org/10.1103/PhysRevLett.115.211101