@article{77a41f85e4e3415eb060eadfdfa31e01,
title = "Precision Measurement of Cosmic-Ray Nitrogen and its Primary and Secondary Components with the Alpha Magnetic Spectrometer on the International Space Station",
abstract = "A precision measurement of the nitrogen flux with rigidity (momentum per unit charge) from 2.2 GV to 3.3 TV based on 2.2×106 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 ΦN can be presented as the sum of its primary component ΦNP and secondary component ΦNS, ΦN=ΦNP+ΦNS, and we found ΦN is well described by the weighted sum of the oxygen flux ΦO (primary cosmic rays) and the boron flux ΦB (secondary cosmic rays), with ΦNP=(0.090±0.002)×ΦO and ΦNS=(0.62±0.02)×ΦB 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.",
author = "{(AMS Collaboration)} and M. Aguilar and {Ali Cavasonza}, L. and B. Alpat and G. Ambrosi and L. Arruda and N. Attig and S. Aupetit and P. Azzarello and A. Bachlechner and F. Barao and A. Barrau and L. Barrin and A. Bartoloni and L. Basara and {Ba{\c s}eǧmez-Du Pree}, S. and M. Battarbee and R. Battiston and U. Becker and M. Behlmann and B. Beischer and J. Berdugo and B. Bertucci and Bindel, {K. F.} and V. Bindi and {De Boer}, W. and K. Bollweg and V. Bonnivard and B. Borgia and Boschini, {M. J.} and M. Bourquin and Bueno, {E. F.} and Burger, {W. J.} 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, {A. I.} and Chen, {G. M.} and Chen, {H. S.} and Y. Chen and L. Cheng and Chou, {H. Y.} and E. Choumilov and V. Choutko and Chung, {C. H.} and C. Clark and Liqiu Wang",
note = "Funding Information: We thank former NASA Administrator Daniel S. Goldin for his dedication to the legacy of the ISS as a scientific laboratory and his decision for NASA to fly AMS as a DOE payload. We also acknowledge the continuous support of the National Aeronautics and Space Administration (NASA) leadership including Charles Bolden and William H. Gerstenmaier and of the Johnson Space Center (JSC) and Marshall Space Flight Center (MSFC) flight control teams which has allowed AMS to operate optimally on the ISS for seven years. We are grateful for the support of Jim Siegrist and his staff of the DOE including resources from the National Energy Research Scientific Computing Center under Contract No. DE-AC02-05CH11231 and the Argonne Leadership Computing Facility under Contract No. DE-AC02-06CH11357. We also acknowledge the continuous support from MIT and its School of Science, Michael Sipser, Marc Kastner, Ernest Moniz, Richard Milner, and Boleslaw Wyslouch. Research supported by S{\'a}o Paulo Research Foundation (FAPESP) Grants No. 2014/19149-7, No. 2015/50378-5, and No. 2016/10222-9, Brazil; CAS, NSFC, MOST, the provincial governments of Shandong, Jiangsu, Guangdong, and the China Scholarship Council, China; Action H2020 MSCA-IF-2015 under Grant No. 707543-MAtISSE, European Union; the Finnish Funding Agency for Innovation (Tekes) Grants No. 40361/01 and No. 40518/03 and the Academy of Finland Grant No. 258963, Finland; CNRS/IN2P3, CNES, Enigmass, and the ANR, France; Pascale Ehrenfreund, DLR under Grant No. 50OO1403 and JARA-HPC under Project No. JARA0052, Germany; INFN and ASI under ASI-INFN Agreements No. 2013-002-R.0 and No. 2014-037-R.0, Italy; the Consejo Nacional de Ciencia y Tecnolog{\'i}a and UNAM, Mexico; FCT under Grant No. PTDC/FIS/122567/2010, Portugal; CIEMAT, IAC, CDTI, and SEIDI-MINECO under Grants No. ESP2015-71662-C2-(1-P/2-P), No. SEV-2015-0548, No. MDM-2015-0509, and No. RyC-2013-14660, Spain; the Swiss National Science Foundation (SNSF), federal and cantonal authorities, Switzerland; Academia Sinica and the Ministry of Science and Technology (MOST) under Grants No. 103-2112-M-006-018-MY3, No. 105-2112-M-001-003, and No. CDA-105-M06, former Presidents of Academia Sinica Yuan-Tseh Lee and Chi-Huey Wong and former Ministers of MOST Maw-Kuen Wu and Luo-Chuan Lee, Taiwan; the Turkish Atomic Energy Authority under Grants No. 2017TAEK(CERN)A5.H6.F2-15, Turkey; and NSF Grants No. 14255202 and No. 1551980, Wyle Laboratories Grant No. 2014/T72497, and NASA NESSF Grant No. HELIO15F-0005, USA. We gratefully acknowledge the strong support from CERN including Rolf-Dieter Heuer, Fabiola Gianotti, and the CERN IT department including Bernd Panzer-Steindel, and from the European Space Agency including Johann-Dietrich W{\"o}rner and Simonetta Di Pippo. We are grateful for important physics discussions with Fiorenza Donato, Jonathan Ellis, Jonathan Feng, Igor Moskalenko, Michael Salamon, Subir Sarkar, Joachim Tr{\"u}mper, Michael S. Turner, and Steven Weinberg. Publisher Copyright: {\textcopyright} 2018 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the «https://creativecommons.org/licenses/by/4.0/» Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.",
year = "2018",
month = jul,
day = "31",
doi = "10.1103/PhysRevLett.121.051103",
language = "English",
volume = "121",
journal = "Physical Review Letters",
issn = "0031-9007",
publisher = "American Physical Society",
number = "5",
}