{"id":73937,"date":"2023-01-12T16:06:35","date_gmt":"2023-01-12T07:06:35","guid":{"rendered":"https:\/\/www.waseda.jp\/inst\/research\/?p=73937"},"modified":"2023-01-12T16:06:35","modified_gmt":"2023-01-12T07:06:35","slug":"cosmic-ray-boron-flux-measured-from8-4gev-n-to-3-8-tev-n-with-the-calorimetric-electron-telescope-on-the-international-space-station%ef%bc%88published-in-physical-review-letters-december-2022","status":"publish","type":"post","link":"https:\/\/www.waseda.jp\/inst\/research\/news\/73937","title":{"rendered":"Cosmic-Ray Boron Flux Measured from8.4GeV\/n to 3.8 TeV\/n with the Calorimetric Electron Telescope on the International Space Station\uff08Published in Physical Review Letters, December 2022\uff09"},"content":{"rendered":"\n\n\n\n\n\n\n\n\n
Journal Title
\n\/\u63b2\u8f09\u30b8\u30e3\u30fc\u30ca\u30eb\u540d<\/td>\n		Physical Review Letters<\/td>\n<\/tr>\n
Publication Year and Month
\n\/\u63b2\u8f09\u5e74\u6708<\/td>\n		December, 2022<\/td>\n<\/tr>\n
Paper Title
\n\/\u8ad6\u6587\u30bf\u30a4\u30c8\u30eb<\/td>\n		Cosmic-Ray Boron Flux Measured from8.4GeV\/n to 3.8 TeV\/n with the Calorimetric Electron Telescope on the International Space Station<\/td>\n<\/tr>\n
DOI
\n\/\u8ad6\u6587DOI<\/td>\n		10.1103\/PhysRevLett.129.251103<\/a><\/td>\n<\/tr>\n
\u00a0Author of Waseda University
\n\/\u672c\u5b66\u306e\u8457\u8005<\/td>\n		AKAIKE, Yosui(Researcher(Associate Professor), Faculty of Science and Engineering, Waseda Research Institute for Science and Engineering):Corresponding Author<\/td>\n<\/tr>\n
Related Websites
\n\/\u95a2\u9023Web<\/td>\n		–<\/td>\n<\/tr>\n
Abstract
\n\/\u6284\u9332<\/td>\n		We present the measurement of the energy dependence of the boron flux in cosmic rays and its ratio to the carbon flux in an energy interval from\u00a08.4<\/span><\/span>\u2009<\/span><\/span><\/span>\u2009<\/span><\/span><\/span>GeV<\/span><\/span>\/<\/span><\/span>n<\/span><\/span><\/span><\/span><\/span><\/span>\u00a0to\u00a03.8<\/span><\/span>\u2009<\/span><\/span><\/span>\u2009<\/span><\/span><\/span>TeV<\/span><\/span>\/<\/span><\/span>n<\/span><\/span><\/span><\/span><\/span><\/span>\u00a0based on the data collected by the Calorimetric Electron Telescope (CALET) during\u00a0\u223c<\/span><\/span>6.4<\/span><\/span>\u2009<\/span><\/span><\/span>\u2009<\/span><\/span><\/span>yr<\/span><\/span><\/span><\/span><\/span>\u00a0of operation on the International Space Station. An update of the energy spectrum of carbon is also presented with an increase in statistics over our previous measurement. The observed boron flux shows a spectral hardening at the same transition energy\u00a0E<\/span><\/span><\/span>0<\/span><\/span><\/span><\/span>\u223c<\/span><\/span>200<\/span><\/span>\u2009<\/span><\/span><\/span>\u2009<\/span><\/span><\/span>GeV<\/span><\/span>\/<\/span><\/span>n<\/span><\/span><\/span><\/span><\/span><\/span>\u00a0of the C spectrum, though B and C fluxes have different energy dependences. The spectral index of the B spectrum is found to be\u00a0\u03b3<\/span><\/span>=<\/span><\/span>\u2212<\/span><\/span>3.047<\/span><\/span>\u00b1<\/span><\/span>0.024<\/span><\/span><\/span><\/span><\/span>\u00a0in the interval\u00a025<\/span><\/span><<\/span><\/span>E<\/span><\/span><<\/span><\/span>200<\/span><\/span>\u2009<\/span><\/span><\/span>\u2009<\/span><\/span><\/span>GeV<\/span><\/span>\/<\/span><\/span>n<\/span><\/span><\/span><\/span><\/span><\/span>. The B spectrum hardens by\u00a0\u0394<\/span><\/span>\u03b3<\/span><\/span><\/span>B<\/span><\/span><\/span><\/span>=<\/span><\/span>0.25<\/span><\/span>\u00b1<\/span><\/span>0.12<\/span><\/span><\/span><\/span><\/span>, while the best fit value for the spectral variation of C is\u00a0\u0394<\/span><\/span>\u03b3<\/span><\/span><\/span>C<\/span><\/span><\/span><\/span>=<\/span><\/span>0.19<\/span><\/span>\u00b1<\/span><\/span>0.03<\/span><\/span><\/span><\/span><\/span>. The\u00a0B<\/span><\/span>\/<\/span><\/span>C<\/span><\/span><\/span><\/span><\/span><\/span>\u00a0flux ratio is compatible with a hardening of\u00a00.09<\/span><\/span>\u00b1<\/span><\/span>0.05<\/span><\/span><\/span><\/span><\/span>, though a single power-law energy dependence cannot be ruled out given the current statistical uncertainties. A break in the\u00a0B<\/span><\/span>\/<\/span><\/span>C<\/span><\/span><\/span><\/span><\/span><\/span>\u00a0ratio energy dependence would support the recent AMS-02 observations that secondary cosmic rays exhibit a stronger hardening than primary ones. We also perform a fit to the\u00a0B<\/span><\/span>\/<\/span><\/span>C<\/span><\/span><\/span><\/span><\/span><\/span>\u00a0ratio with a leaky-box model of the cosmic-ray propagation in the Galaxy in order to probe a possible residual value\u00a0\u03bb<\/span><\/span><\/span>0<\/span><\/span><\/span><\/span><\/span><\/span><\/span>\u00a0of the mean escape path length\u00a0\u03bb<\/span><\/span><\/span><\/span><\/span>\u00a0at high energy. We find that our\u00a0B<\/span><\/span>\/<\/span><\/span>C<\/span><\/span><\/span><\/span><\/span><\/span>\u00a0data are compatible with a nonzero value of\u00a0\u03bb<\/span><\/span><\/span>0<\/span><\/span><\/span><\/span><\/span><\/span><\/span>, which can be interpreted as the column density of matter that cosmic rays cross within the acceleration region.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"excerpt":{"rendered":"

Journal Title \/\u63b2\u8f09\u30b8\u30e3\u30fc\u30ca\u30eb\u540d Physical Review Letters Publication Year and Month \/\u63b2\u8f09\u5e74\u6708 December, 2022 Paper Title \/\u8ad6 […]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[],"tags":[218,217],"class_list":["post-73937","post","type-post","status-publish","format-standard","hentry","tag-impact-en","tag-impact"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.waseda.jp\/inst\/research\/wp-json\/wp\/v2\/posts\/73937","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.waseda.jp\/inst\/research\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.waseda.jp\/inst\/research\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.waseda.jp\/inst\/research\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.waseda.jp\/inst\/research\/wp-json\/wp\/v2\/comments?post=73937"}],"version-history":[{"count":1,"href":"https:\/\/www.waseda.jp\/inst\/research\/wp-json\/wp\/v2\/posts\/73937\/revisions"}],"predecessor-version":[{"id":73938,"href":"https:\/\/www.waseda.jp\/inst\/research\/wp-json\/wp\/v2\/posts\/73937\/revisions\/73938"}],"wp:attachment":[{"href":"https:\/\/www.waseda.jp\/inst\/research\/wp-json\/wp\/v2\/media?parent=73937"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.waseda.jp\/inst\/research\/wp-json\/wp\/v2\/categories?post=73937"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.waseda.jp\/inst\/research\/wp-json\/wp\/v2\/tags?post=73937"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}