Open Access

Properties of Heavy Cosmic Nuclei Phosphorus, Chlorine, Argon, Potassium, and Calcium: Results from the Alpha Magnetic Spectrometer

A. Aceituno²⁹, M. Aguilar²⁹, B. Alpat³⁵, G. Ambrosi³⁵, H. Anderson⁹, J. Antunes^21,26, L. Arruda ²⁶, N. Attig²³, C. Bagwell⁹ et al. (AMS Collaboration)

C. Bagwell⁹, F. Barao ^26,27, M. Barbanera³⁵, L. Barrin¹³, A. Bartoloni ³⁹, R. Battiston^46,47, A. Bayyari¹⁹, N. Belyaev⁹, B. Bertucci ^35,36, V. Bindi¹⁹, K. Bollweg²⁰, J. Bolster⁹, M. Borchiellini¹⁶, B. Borgia ^39,40, M. J. Boschini³¹, M. Bourquin¹⁴, C. Brugnoni^35,36, W. J. Burger⁴⁶, H. Y. Cai^5,6, X. D. Cai⁹, M. Capell ⁹, J. Casaus²⁹, J. Cassidy²⁰, G. Castellini¹², F. Cervelli³⁷, Y. H. Chang^44,45, G. M. Chen^5,6, G. R. Chen²², H. Chen¹⁸, H. Chen^5,6, H. S. Chen^5,6, Y. Chen²², L. Cheng²², H. Y. Chou⁴⁴, S. Chouridou¹, V. Choutko⁹, C. H. Chung¹, C. Clark²⁰, G. Coignet³, C. Consolandi¹⁹, A. Contin ^7,8, C. Corti¹⁹, Y. X. Cui^5,6, Z. Cui^21,22, K. Dadzie⁹, F. D’Angelo^7,8, A. Dass¹⁹, C. Delgado²⁹, S. Della Torre³¹, M. B. Demirköz ², L. Derome¹⁵, S. Di Falco ³⁷, V. Di Felice⁴¹, C. Díaz²⁹, F. Dimiccoli^46,47, P. von Doetinchem ¹⁹, F. Dong³³, M. Dotson²⁰, M. Duranti ³⁵, A. Egorov⁹, A. Ellison²⁰, F. Faldi^35,36, D. Fehr¹, J. Feng ¹⁷, E. Fiandrini^35,36, P. Fisher⁹, V. Formato ⁴¹, R. J. García-López²⁵, A. Galdames⁹, C. Gargiulo¹³, H. Gast¹, T. T. Ge¹⁷, M. Gervasi^31,32, L. E. Ghezzer^46,47, F. Giovacchini²⁹, D. M. Gómez-Coral ³⁰, J. Gong³³, D. Grandi^31,32, M. Graziani ^35,36, R. Guidetti^31,32, C. Guan²¹, Z. H. He¹⁷, B. Heber²⁴, F. Hernández-Nicolás²⁹, L. Höfer¹, T. H. Hsieh⁹, J. Y. Hu³⁵, B. W. Huang¹⁸, M. Ionica³⁵, M. Incagli ³⁷, Yi Jia ⁹, H. Jinchi²⁸, T. Kappe¹, E. Karadöller², G. Karagöz², J. Kastelic²⁰, Th. Kirn¹, O. Kounina⁹, A. Kounine⁹, V. Koutsenko⁹, D. Krasnopevtsev ⁹, A. Kuhlman¹⁹, A. Kulemzin⁹, G. La Vacca^31,32, E. Laudi¹³, G. Laurenti⁷, I. Lazzizzera ^46,47, H. T. Lee⁴³, S. C. Lee⁴⁴, H. L. Li²², J. H. Li¹⁷, J. Q. Li³³, M. Li ²¹, Q. Li³³, Q. Li²¹, Q. Y. Li²², S. L. Li⁵, Z. H. Li^5,6, P. Liao²¹, C. H. Lin⁴⁴, T. Lippert²³, P. C. Liu²², Z. Liu⁴¹, S. Q. Lu ^5,44, J. Z. Luo³³, Q. Luo¹⁷, S. D. Luo¹⁸, Xi Luo²², C. Mañá²⁹, J. Marín²⁹, G. Martínez²⁹, N. Masi ⁷, D. Maurin¹⁵, T. Medvedeva ⁹, A. Menchaca-Rocha³⁰, Q. Meng³³, V. V. Mikhailov²², M. Molero ²⁹, P. Mott²⁰, L. Mussolin^35,36, Y. Najafi Jozani¹, R. Nicolaidis^46,47, N. Nikonov¹⁹, F. Nozzoli ⁴⁶, J. Ocampo-Peleteiro⁷, A. Oliva ⁷, M. Orcinha ^35,36, F. Palmonari ^7,8, M. Paniccia ¹⁴, A. Pashnin⁹, M. Pauluzzi^35,36, D. Pelosi^35,36, S. Pensotti^31,32, D. Perez⁹, P. Pietzcker²⁴, V. Plyaskin⁹, S. Poluianov³⁴, D. Pridöhl¹, N. Puccetti^46,47, Z. Y. Qu²², L. Quadrani^7,8, M. M. Rafiei³⁹, P. G. Rancoita³¹, D. Rapin¹⁴, E. Robyn⁷, I. Rodríguez-García²⁹, L. Romaneehsen²⁴, F. Rossi ^46,47, A. Rozhkov⁹, D. Rozza ^31,32, R. Sagdeev¹⁰, S. Schael¹, A. Schultz von Dratzig¹, G. Schwering¹, E. S. Seo¹¹, B. S. Shan⁴, A. Shukla¹⁹, T. Siedenburg¹, A. Siemko⁹, G. Silvestre³⁵, D. Schledewitz^46,47, J. W. Song²¹, X. J. Song²², R. Sonnabend¹, A. Strekalovsky⁹, L. Strigari^39,*, A. Stuzhin²¹, T. Su²², Q. Sun²¹, Z. T. Sun⁵, L. Tabarroni⁴¹, M. Tacconi ^31,32, Z. C. Tang ⁵, J. J. Teoh^5,6, J. Tian⁴¹, Ye Tian^5,6, Y. Tian¹⁸, Samuel C. C. Ting ^9,13, S. M. Ting⁹, N. Tomassetti^35,36, J. Torsti⁴⁸, A. Ubaldi^35,36, I. Usoskin³⁴, V. Vagelli ^38,35, R. Vainio⁴⁸, P. Väisänen³⁴, M. Valencia-Otero⁴⁴, E. Valente^39,40, E. Valtonen⁴⁸, E. Van Hove⁹, M. Vázquez Acosta ²⁵, M. Vecchi¹⁶, M. Velasco²⁹, J. C. Wang⁵, L. Q. Wang²¹, N. H. Wang²¹, S. Wang¹⁹, X. Wang⁹, Z. M. Wang²², M. Waqas⁴¹, Z. L. Weng ⁹, H. Wu³³, Z. B. Wu²¹, J. N. Xiao¹⁸, R. Q. Xiong³³, Y. Z. Xiong¹⁸, W. Xu ^21,22, Q. Yan ^5,6, Z. X. Yan^5,6, H. T. Yang^5,6, Y. Yang^42,44, H. Yi³³, Y. H. You^5,6, M. Yu²¹, Y. M. Yu⁹, Z. Q. Yu⁵, B. Q. Yuan²², C. Zhang ⁵, F. Z. Zhang⁵, J. Zhang²¹, J. H. Zhang³³, Z. Zhang⁹, P. W. Zhao¹⁷, Z. M. Zheng⁴, H. F. Zhou¹⁷, H. L. Zhuang⁵, V. Zhukov ¹, L. K. Zou²², M. Zuberi⁹, and P. Zuccon^46,47 (AMS Collaboration)

¹I. Physics Institute and JARA-FAME, RWTH Aachen University, 52056 Aachen, Germany
²Department of Physics, Middle East Technical University (METU), 06800 Ankara, Türkiye
³Université Grenoble Alpes, Université Savoie Mont Blanc, CNRS, LAPP-IN2P3, 74000 Annecy, France
⁴Beihang University (BUAA), Beijing, 100191, China
⁵Institute of High Energy Physics (IHEP), Chinese Academy of Sciences, Beijing, 100049, China
⁶University of Chinese Academy of Sciences (UCAS), Beijing, 100049, China
⁷INFN Sezione di Bologna, 40126 Bologna, Italy
⁸Università di Bologna, 40126 Bologna, Italy
⁹Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139, USA
¹⁰East-West Center for Space Science, University of Maryland, College Park, Maryland 20742, USA
¹¹IPST, University of Maryland, College Park, Maryland 20742, USA
¹²CNR–IROE, 50125 Firenze, Italy
¹³European Organization for Nuclear Research (CERN), 1211 Geneva 23, Switzerland
¹⁴DPNC, Université de Genève, 1211 Genève 4, Switzerland
¹⁵Université Grenoble Alpes, CNRS, Grenoble INP, LPSC-IN2P3, 38000 Grenoble, France
¹⁶Kapteyn Astronomical Institute, University of Groningen, P.O. Box 800, 9700 AV Groningen, Netherlands
¹⁷Sun Yat–sen University (SYSU), Guangzhou, 510275, China
¹⁸Zhejiang University (ZJU), Hangzhou 310058, China
¹⁹Physics and Astronomy Department, University of Hawaii, Honolulu, Hawaii 96822, USA
²⁰National Aeronautics and Space Administration Johnson Space Center (JSC), Houston, Texas 77058, USA and Goddard Space Flight Center (GSFC), Greenbelt, Maryland 20771, USA
²¹Shandong University (SDU), Jinan, Shandong, 250100, China
²²Shandong Institute of Advanced Technology (SDIAT), Jinan, Shandong, 250100, China
²³Jülich Supercomputing Centre and JARA-FAME, Research Centre Jülich, 52425 Jülich, Germany
²⁴Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24118 Kiel, Germany
²⁵Instituto de Astrofísica de Canarias (IAC), 38205 La Laguna, Santa Cruz de Tenerife, Spain and Departamento de Astrofísica, Universidad de La Laguna, 38206 La Laguna, Tenerife, Spain
²⁶Laboratório de Instrumentação e Física Experimental de Partículas (LIP), 1649-003 Lisboa, Portugal
²⁷Departamento de Física, Instituto Superior Técnico (IST), Universidade de Lisboa, 1049-001 Lisboa, Portugal
²⁸National Chung–Shan Institute of Science and Technology (NCSIST), Longtan, Tao Yuan, 32546, Taiwan
²⁹Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), 28040 Madrid, Spain
³⁰Instituto de Física, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, 01000 Mexico
³¹INFN Sezione di Milano–Bicocca, 20126 Milano, Italy
³²Università di Milano–Bicocca, 20126 Milano, Italy
³³Southeast University (SEU), Nanjing, 210096, China
³⁴Sodankylä Geophysical Observatory and Space Physics and Astronomy Research Unit, University of Oulu, 90014 Oulu, Finland
³⁵INFN Sezione di Perugia, 06100 Perugia, Italy
³⁶Università di Perugia, 06100 Perugia, Italy
³⁷INFN Sezione di Pisa, 56100 Pisa, Italy
³⁸Agenzia Spaziale Italiana (ASI), 00133 Roma, Italy
³⁹INFN Sezione di Roma 1, 00185 Roma, Italy
⁴⁰Università di Roma La Sapienza, 00185 Roma, Italy
⁴¹INFN Sezione di Roma Tor Vergata, 00133 Roma, Italy
⁴²National Cheng Kung University, Tainan, 70101, Taiwan
⁴³Academia Sinica Grid Center (ASGC), Nankang, Taipei, 11529, Taiwan
⁴⁴Institute of Physics, Academia Sinica, Nankang, Taipei, 11529, Taiwan
⁴⁵Physics Department and Center for High Energy and High Field Physics, National Central University (NCU), Tao Yuan, 32054, Taiwan
⁴⁶INFN TIFPA, 38123 Trento, Italy
⁴⁷Università di Trento, 38123 Trento, Italy
⁴⁸Space Research Laboratory, Department of Physics and Astronomy, University of Turku, 20014 Turku, Finland

^*Also at IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy.

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Phys. Rev. Lett. 136, 241002 – Published 17 June, 2026

DOI: https://doi.org/10.1103/d2vf-fw3v

Abstract

We report the unique properties of cosmic phosphorus (P), chlorine (Cl), argon (Ar), potassium (K), and calcium (Ca) fluxes in the GV to TV rigidity range collected by the Alpha Magnetic Spectrometer (AMS) on the International Space Station. With a total of one million events collected over 13.5 years, we observed that the rigidity dependencies of the five fluxes are well described by the sums of a primary cosmic ray component and a secondary cosmic ray component. The abundance ratios of all five elements to Si at the source are accurately determined independent of cosmic ray propagation. The source abundance of Ar and Ca (even- $Z$ elements) is larger than P, Cl, and K (odd- $Z$ elements). The secondary components of the P and the Cl fluxes are each $\sim 1 / 3$ of the F flux, and the secondary components of the Ar, K, and Ca fluxes are each $\sim 1 / 2$ of the F flux. The twenty elements measured by AMS, from He to Ca and Fe, can be categorized into four classes, two primary and two secondary, based on their rigidity dependence.

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References (40)

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Phys. Rev. Lett. 136, 241002– Published 17 June, 2026

Vol. 136, Iss. 24 — 19 June 2026

Received 23 February 2026
Accepted 30 April 2026

DOI: https://doi.org/10.1103/d2vf-fw3v

Published by the American Physical Society under the terms of the 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. Open access publication funded by CERN.

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Properties of Heavy Cosmic Nuclei Phosphorus, Chlorine, Argon, Potassium, and Calcium: Results from the Alpha Magnetic Spectrometer

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