研究者情報 | 神奈川大学

タムラ　タダヒサ Tamura Tadahisa 田村　忠久所属神奈川大学工学部応用物理学科神奈川大学大学院工学研究科工学専攻（応用物理学領域）職種教授
言語種別	英語
発行・発表の年月	2023/04
形態種別	学術雑誌
査読	査読あり
標題	Direct Measurement of the Cosmic-Ray Helium Spectrum from 40 GeV to 250 TeV with the Calorimetric Electron Telescope on the International Space Station
執筆形態	共著
掲載誌名	PHYSICAL REVIEW LETTERS
掲載区分	国外
出版社・発行元	the American Physical Society
巻・号・頁	130(171002),pp.1-8
国際共著	国際共著
著者・共著者	O. Adriani, et al.
概要	We present the results of a direct measurement of the cosmic-ray helium spectrum with the CALET instrument. The measured spectrum shows evidence of a deviation of the flux from a single power law by more than 8σ with a progressive spectral hardening from a few hundred GeV to a few tens of TeV. This result is consistent with the data reported by space instruments including PAMELA, AMS-02, and DAMPE and balloon instruments including CREAM. At higher energy we report the onset of a softening of the helium spectrum around 30 TeV. A double broken power law is found to fit simultaneously both spectral features: the hardening (at lower energy) and the softening (at higher energy). A measurement of the proton to helium flux ratio in the energy range from 60 GeV/n to about 60 TeV/n is also presented, using the CALET proton flux recently updated with higher statistics.