Direct Measurement of the Nickel Spectrum in Cosmic Rays in the Energy Range from 8.8  GeV/n to 240  GeV/n with CALET on the International Space Station

Adriani, O.; Akaike, Y.; Asano, K.; Asaoka, Y.; Cannady, Nicholas; Hams, T.; Sakai, K.; et al

Direct Measurement of the Nickel Spectrum in Cosmic Rays in the Energy Range from 8.8 GeV/n to 240 GeV/n with CALET on the International Space Station

dc.contributor.author	Adriani, O.
dc.contributor.author	Akaike, Y.
dc.contributor.author	Asano, K.
dc.contributor.author	Asaoka, Y.
dc.contributor.author	Cannady, Nicholas
dc.contributor.author	Hams, T.
dc.contributor.author	Sakai, K.
dc.contributor.author	et al
dc.date.accessioned	2022-05-10T16:04:12Z
dc.date.available	2022-05-10T16:04:12Z
dc.date.issued	2022-04-01
dc.description	Authors: O. Adriani, Y. Akaike,, K. Asano, Y. Asaoka, E. Berti, G. Bigongiari,, W. R. Binns, M. Bongi, P. Brogi, A. Bruno, J. H. Buckley, N. Cannady,, G. Castellini, C. Checchia ,, M. L. Cherry, G. Collazuol, K. Ebisawa, A. W. Ficklin, H. Fuke, S. Gonzi, T. G. Guzik, T. Hams, K. Hibino, M. Ichimura, K. Ioka, W. Ishizaki, M. H. Israel, K. Kasahara, J. Kataoka, R. Kataoka, Y. Katayose, C. Kato, N. Kawanaka, Y. Kawakubo, K. Kobayashi, K. Kohri, H. S. Krawczynski, J. F. Krizmanic, P. Maestro, P. S. Marrocchesi, A. M. Messineo, J. W. Mitchell, S. Miyake, A. A. Moiseev,, M. Mori, N. Mori, H. M. Motz, K. Munakata, S. Nakahira, J. Nishimura, G. A. de Nolfo, S. Okuno, J. F. Ormes, N. Ospina, S. Ozawa, L. Pacini,, P. Papini, B. F. Rauch, S. B. Ricciarini, K. Sakai,, T. Sakamoto, M. Sasaki,, Y. Shimizu, A. Shiomi, P. Spillantini, F. Stolzi,, S. Sugita, A. Sulaj, M. Takita, T. Tamura, T. Terasawa, S. Torii, Y. Tsunesada, Y. Uchihori, E. Vannuccini, J. P. Wefel, K. Yamaoka, S. Yanagita, A. Yoshida, K. Yoshida, and W. V. Zober	en_US
dc.description.abstract	The relative abundance of cosmic ray nickel nuclei with respect to iron is by far larger than for all other transiron elements; therefore it provides a favorable opportunity for a low background measurement of its spectrum. Since nickel, as well as iron, is one of the most stable nuclei, the nickel energy spectrum and its relative abundance with respect to iron provide important information to estimate the abundances at the cosmic ray source and to model the Galactic propagation of heavy nuclei. However, only a few direct measurements of cosmic-ray nickel at energy larger than ∼3 GeV/n are available at present in the literature, and they are affected by strong limitations in both energy reach and statistics. In this Letter, we present a measurement of the differential energy spectrum of nickel in the energy range from 8.8 to 240 GeV/n, carried out with unprecedented precision by the Calorimetric Electron Telescope (CALET) in operation on the International Space Station since 2015. The CALET instrument can identify individual nuclear species via a measurement of their electric charge with a dynamic range extending far beyond iron (up to atomic number Z=40). The particle’s energy is measured by a homogeneous calorimeter (1.2 proton interaction lengths, 27 radiation lengths) preceded by a thin imaging section (3 radiation lengths) providing tracking and energy sampling. This Letter follows our previous measurement of the iron spectrum [O. Adriani et al. (CALET Collaboration), Phys. Rev. Lett. 126, 241101 (2021).], and it extends our investigation on the energy dependence of the spectral index of heavy elements. It reports the analysis of nickel data collected from November 2015 to May 2021 and a detailed assessment of the systematic uncertainties. In the region from 20 to 240 GeV/n our present data are compatible within the errors with a single power law with spectral index −2.51±0.07.	en_US
dc.description.sponsorship	We gratefully acknowledge JAXA’s contributions to the development of CALET and to the operations aboard the JEM-EF on the International Space Station. We also wish to express our sincere gratitude to ASI (Agenzia Spaziale Italiana) and NASA for their support of the CALET project. This work was supported in part by JSPS KAKENHI Grants No. 26220708, No. 19H05608, No. 17H02901, No. 21K03592, and No. 20K22352 and by the MEXT-Supported Program for the Strategic Research Foundation at Private Universities (2011-2015) (No. S1101021) at Waseda University. The CALET effort in Italy is supported by ASI under Agreement No. 2013-018-R.0 and its amendments. The CALET effort in the United States is supported by NASA through Grants No. 80NSSC20K0397, No. 80NSSC20K0399, and No. NNH18ZDA001N-APRA18-0004	en_US
dc.description.uri	https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.128.131103	en_US
dc.format.extent	8 pages	en_US
dc.genre	journal articles	en_US
dc.identifier	doi:10.13016/m2bjwt-snbq
dc.identifier.citation	"Adriani, O. et al. Direct Measurement of the Nickel Spectrum in Cosmic Rays in the Energy Range from 8.8 GeV=n to 240 GeV=n with CALET on the International Space Station. PHYSICAL REVIEW LETTERS 128 (2022) 131103. https://doi.org/10.1103/PhysRevLett.128.131103"	en_US
dc.identifier.uri	https://doi.org/10.1103/PhysRevLett.128.131103
dc.identifier.uri	http://hdl.handle.net/11603/24676
dc.language.iso	en_US	en_US
dc.publisher	APS	en_US
dc.relation.isAvailableAt	The University of Maryland, Baltimore County (UMBC)
dc.relation.ispartof	UMBC Center for Space Sciences and Technology
dc.relation.ispartof	UMBC Faculty Collection
dc.rights	This item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.	en_US
dc.rights	Attribution 4.0 International (CC BY 4.0)	*
dc.rights.uri	https://creativecommons.org/licenses/by/4.0/	*
dc.title	Direct Measurement of the Nickel Spectrum in Cosmic Rays in the Energy Range from 8.8 GeV/n to 240 GeV/n with CALET on the International Space Station	en_US
dc.type	Text	en_US
dcterms.creator	https://orcid.org/0000-0003-2916-6955	en_US