Precision Spectral Measurements of Chromium and Titanium from 10 to <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mn>250</mml:mn><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi>GeV</mml:mi><mml:mo>/<

The Calorimetric Electron Telescope (CALET), in operation on the International Space Station since 2015, collected a large sample of cosmic-ray (CR) iron and sub-iron events over a wide energy interval. In this Letter, we report an update of our previous measurement of the iron flux and we present-for the first time-a high statistics measurement of the spectra of two sub-iron elements Cr and Ti in the energy interval from 10 to 250 GeV/n. The analyses are based on 8 years of data. Differently from older generations of cosmic-ray instruments which, in most cases, could not resolve individual sub-iron elements, CALET can identify each nuclear species from proton to nickel (and beyond) with a measurement of their electric charge. Thanks to the improvement in statistics and a more refined assessment of systematic uncertainties, the iron spectral shape is better resolved, at high energy, than in our previous paper, and we report its flux ratio to chromium and titanium. The measured fluxes of Cr and Ti show energy dependences compatible with a single power law with spectral indices -2.74±0.06 and -2.88±0.06, respectively.

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Journal
Physical Review Letters
Published
2025-06-18
DOI
https://doi.org/10.1103/py17-74rk
Primary Topic
X-ray Spectroscopy and Fluorescence Analysis
Type
article
Field-Weighted Citation Impact
0.00

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article

Precision Spectral Measurements of Chromium and Titanium from 10 to <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mn>250</mml:mn><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi>GeV</mml:mi><mml:mo>/<

Giovanni Castellini, G. A. de Nolfo, S. Ricciarini, K Yoshida et al.
Physical Review Letters
X-ray Spectroscopy and Fluorescence Analysis
article

Precision Spectral Measurements of Chromium and Titanium from 10 to <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mn>250</mml:mn><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi>GeV</mml:mi><mml:mo>/<

Giovanni Castellini, G. A. de Nolfo, S. Ricciarini, K Yoshida, John Krizmanic, Y. Katayose, Kazunori Kohri, N. Mōri, C. Checchia, S. Yanagita, M. Ichimura, Wolfgang V Zober, K. Kasahara, T. Tamura, Jun Kataoka, Yuki Shimizu, M. Mattiazzi, T. Hams, M. Bongi, K. Hibino, Ayano Yoshida, Y. Asaoka, S. Okuno, P. Papini, J. P. Wefel, Keiichi Yamaoka, E. Berti, Shoko Miyake, L. Pacini, M. H. Israel, J. Nishimura, S. Ozawa, T. G. Guzik, G. Bigongiari, P. Betti, Tsubasa Sakamoto, Holger Motz, H. Fuke, S Nakahira, Ken Ebisawa, P. Brogi, T. Terasawa, Norita Kawanaka, H. Krawczynski, Katsuaki Asano, Michela Negro, M Mori, F. Stolzi, Anthony W. Ficklin, M Sasaki, K. Munakata, A Shiomi, Yosui Akaike, A. Bruno, S. Sugita, W. R. Binns, M. L. Cherry, Y. Kawakubo, E. Vannuccini, Ryuho Kataoka, B. F. Rauch, Kazuo Sakai, P. Maestro, A. Messineo, S. Gonzi, G. Collazuol, Shuki Torii, N. Cannady, Kazuyoshi Kobayashi, Alexander Moiseev, Y. Tsunesada, J. F. Ormes, Y. Uchihori, П. Спиллантини, P.S. Marrocchesi, M. Takita, A. Sulaj, C. Kato, J. W. Mitchell, Karl J. Friston
article en

Abstract

The Calorimetric Electron Telescope (CALET), in operation on the International Space Station since 2015, collected a large sample of cosmic-ray (CR) iron and sub-iron events over a wide energy interval. In this Letter, we report an update of our previous measurement of the iron flux and we present-for the first time-a high statistics measurement of the spectra of two sub-iron elements Cr and Ti in the energy interval from 10 to 250 GeV/n. The analyses are based on 8 years of data. Differently from older generations of cosmic-ray instruments which, in most cases, could not resolve individual sub-iron elements, CALET can identify each nuclear species from proton to nickel (and beyond) with a measurement of their electric charge. Thanks to the improvement in statistics and a more refined assessment of systematic uncertainties, the iron spectral shape is better resolved, at high energy, than in our previous paper, and we report its flux ratio to chromium and titanium. The measured fluxes of Cr and Ti show energy dependences compatible with a single power law with spectral indices -2.74±0.06 and -2.88±0.06, respectively.

Physical Review LettersVol. 135(2)
University of Siena (IT), Nihon University (JP), University of Pisa (IT), Louisiana State University (US), Goddard Space Flight Center (US), Aoyama Gakuin University (JP), University of Denver (US), Ritsumeikan University (JP), Shinshu University (JP), University of Padua (IT), High Energy Accelerator Research Organization (JP), Hirosaki University (JP), Waseda University (JP), Shibaura Institute of Technology (JP), Yokohama National University (JP), Washington University in St. Louis (US), Japan Aerospace Exploration Agency (JP), Laboratoire AstroParticule et Cosmologie (FR), National Institute of Polar Research (JP), University of Chicago (US), Kanagawa University (JP), Nello Carrara Institute of Applied Physics (IT), Heliophysics (US), Istituto Nazionale di Fisica Nucleare, Sezione di Padova (IT), National Institute of Technology, Gifu College (JP), National Institutes for Quantum Science and Technology (JP), National Institute of Technology (JP), Istituto Nazionale di Fisica Nucleare, Sezione di Firenze (IT), Institute of Nuclear and Particle Physics (GR), Institute of Space and Astronautical Science (JP), Helios Kliniken (DE), SpaceX (United States) (US), National Research Council (IT), National Astronomical Observatory of Japan (JP), Istituto Nazionale di Fisica Nucleare, Sezione di Pisa (IT), Ōtani University (JP), Osaka Metropolitan University (JP), Deleted Institution, Institute of Particle and Nuclear Studies, University of Florence (IT), College of Industrial Technology (JP), Nagoya University (JP), Ibaraki University (JP), University of Maryland, College Park (US), Tokyo Metropolitan University (JP), The University of Tokyo (JP), University of Maryland, Baltimore County (US), National Institute of Information and Communications Technology (JP)
National Aeronautics and Space Administration, Ministry of Education, Culture, Sports, Science and Technology, Agenzia Spaziale Italiana, Waseda University, Japan Society for the Promotion of Science, Japan Aerospace Exploration Agency
Openalex Percentile: Top 80%
X-ray Spectroscopy and Fluorescence Analysis
DOIOpen Access PDFOpenAlex
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