Precision Measurement of Cosmic-Ray Nitrogen and its Primary and Secondary Components with the Alpha Magnetic Spectrometer on the International Space Station

Journal Article · 31 July 2018 · Physical Review Letters

DOI: https://doi.org/10.1103/PhysRevLett.121.051103 · OSTI ID:1462307

Aguilar, M.; Ali Cavasonza, L.; Alpat, B.; Ambrosi, G.; Arruda, L.; Attig, N.; Aupetit, S.; Azzarello, P.; Bachlechner, A.; Barao, F.; Barrau, A.; Barrin, L.; Bartoloni, A.; Basara, L.; Başeğmez-du Pree, S.; Battarbee, M.; Battiston, R.; Becker, U.; Behlmann, M.; Beischer, B. ; Berdugo, J.; Bertucci, B.; Bindel, K. F.; Bindi, V.; de Boer, W.; Bollweg, K.; Bonnivard, V.; 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, A. I.; Chen, G. M.; Chen, H. S.; Chen, Y.; Cheng, L.; Chou, H. Y.; Choumilov, E.; Choutko, V.; Chung, C. H.; Clark, C.; Clavero, R.; Coignet, G.; Consolandi, C.; Contin, A.; Corti, C.; Creus, W.; Crispoltoni, M.; Cui, Z.; Dadzie, K.; Dai, Y. M.; Datta, A.; Delgado, C.; Della Torre, S.; Demirköz, M. B.; Derome, L.; Di Falco, S.; Dimiccoli, F.; Díaz, C.; von Doetinchem, P.; Dong, F.; Donnini, F.; Duranti, M.; Egorov, A.; Eline, A.; Eronen, T.; Feng, J.; Fiandrini, E.; Fisher, P.; Formato, V.; Galaktionov, Y.; Gallucci, G.; García-López, R. J.; Gargiulo, C.; Gast, H.; Gebauer, I.; Gervasi, M.; Ghelfi, A.; 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.; Heil, M.; Hsieh, T. H.; Huang, H.; Huang, Z. C.; Incagli, M.; Jia, Yi; Jinchi, H.; Kanishev, K.; Khiali, B.; Kirn, Th.; Konak, C.; Kounina, O.; Kounine, A.; Koutsenko, V.; Kulemzin, A.; La Vacca, G.; Laudi, E.; Laurenti, G.; Lazzizzera, I.; Lebedev, A.; Lee, H. T.; Lee, S. C.; Leluc, C.; Li, H. S.; Li, J. Q.; Li, Q.; Li, T. X.; Li, Z. H.; Li, Z. Y.; Lin, C. H.; Lipari, P.; Lippert, T.; Liu, D.; Liu, Hu; Liu, Z.; Lordello, V. D.; Lu, S. Q.; Lu, Y. S.; Luebelsmeyer, K.; Luo, F.; Luo, J. Z.; Lyu, S. S.; Machate, F.; Mañá, C.; Marín, J.; Martin, T.; Martínez, G.; Masi, N.; Maurin, D.; Menchaca-Rocha, A.; Meng, Q.; Mikuni, V. M.; Mo, D. C.; Mott, P.; Mussolin, L.; Nelson, T.; Ni, J. Q.; Nikonov, N.; Nozzoli, F.; Oliva, A.; Orcinha, M.; Palermo, M.; Palmonari, F.; Palomares, C.; Paniccia, M.; Pauluzzi, M.; Pensotti, S.; Perrina, C.; Phan, H. D.; Picot-Clemente, N.; Pilo, F.; Plyaskin, V.; Pohl, M.; Poireau, V.; Quadrani, L.; Qi, X. M.; Qin, X.; Qu, Z. Y.; Räihä, T.; Rancoita, P. G.; Rapin, D.; Ricol, J. S.; Rosier-Lees, S.; Rozhkov, A.; Rozza, D.; Sagdeev, R.; Schael, S.; Schmidt, S. M.; Schulz von Dratzig, A.; Schwering, G.; Seo, E. S.; Shan, B. S.; Shi, J. Y.; Siedenburg, T.; Song, J. W.; Tacconi, M.; Tang, X. W.; Tang, Z. C.; Tescaro, D.; Tian, J.; Ting, Samuel C. C.; Ting, S. M.; Tomassetti, N.; Torsti, J.; Urban, T.; Vagelli, V.; Valente, E.; Valtonen, E.; Vázquez Acosta, M.; Vecchi, M.; Velasco, M.; Vialle, J. P.; Wang, L. Q.; Wang, N. H.; Wang, Q. L.; Wang, X.; Wang, X. Q.; Wang, Z. X.; Wei, C. C.; Wei, J.; Weng, Z. L.; Whitman, K.; Wu, H.; Xiong, R. Q.; Xu, W.; Yan, Q.; Yang, M.; Yang, Y.; Yi, H.; Yu, Y. J.; Yu, Z. Q.; Zannoni, M.; Zeissler, S.; Zhang, C.; Zhang, F.; Zhang, J.; Zhang, J. H.; Zhang, S. W.; Zhang, Z.; Zheng, Z. M.; Zhuang, H. L.; Zhukov, V.; Zichichi, A.; Zimmermann, N.; Zuccon, P.

A precision measurement of the nitrogen flux with rigidity (momentum per unit charge) from 2.2 GV to 3.3 TV based on 2.2 × 10$^6$ events is presented. The detailed rigidity dependence of the nitrogen flux spectral index is presented for the first time. The spectral index rapidly hardens at high rigidities and becomes identical to the spectral indices of primary He, C, and O cosmic rays above ~ 700 GV . We observed that the nitrogen flux $$Φ_N$$ can be presented as the sum of its primary component $$Φ^P_N$$ and secondary component $$Φ^S_N$$ , $$Φ_N$$ = $$Φ^P_N$$ + $$Φ^S_N$$ , and we found $$Φ_N$$ is well described by the weighted sum of the oxygen flux $$Φ_O$$ (primary cosmic rays) and the boron flux $$Φ_B$$ (secondary cosmic rays), with $$Φ^P_N$$ = (0.090 ± 0.002) × $$Φ_O$$ and $$Φ^S_N$$ = (0.62 ± 0.02) × $$Φ_B$$ over the entire rigidity range. This corresponds to a change of the contribution of the secondary cosmic ray component in the nitrogen flux from 70% at a few GV to < 30 % above 1 TV.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)
• Sponsoring Organization: USDOE Office of Science (SC)
• Contributing Organization: AMS Collaboration
• Grant/Contract Number: AC02-06CH11357; 2014/19149-7; 2015/50378-5; 2016/10222-9; 707543-MAtISSE; 40361/01; 40518/03; 258963; 50OO1403; 2013-002-R.0; 2014-037-R.0; PTDC/FIS/122567/2010; ESP2015-71662-C2-(1-P/2-P); SEV-2015-0548; MDM-2015-0509; RyC-2013-14660; 103-2112-M-006-018-MY3; 105-2112-M-001-003; CDA-105-M06; 2017TAEK(CERN)A5.H6.F2-15; 14255202; 1551980; HELIO15F-0005; AC02-05CH11231; JARA0052; 2014/T72497
• OSTI ID: 1462307
• Alternate ID(s): OSTI ID: 1544242
• Journal Information: Physical Review Letters, Vol. 121, Issue 5; ISSN 0031-9007
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English