Extended measurement of the proton spectrum with CALET on the International Space Station

Discussion timeslot (ZOOM-Meeting): 14. July 2021 - 18:00
ZOOM-Meeting URL: https://desy.zoom.us/j/91896950007
ZOOM-Meeting ID: 91896950007
ZOOM-Meeting Passcode: ICRC2021
Corresponding Session: https://icrc2021-venue.desy.de/channel/17-Nuclear-CR-spectra-theory-and-observations-CRD/115
Live-Stream URL: https://icrc2021-venue.desy.de/livestream/Discussion-06/7

Abstract:
'Calorimetric Electron Telescope (CALET) is aiming to measure the main components of high energy cosmic rays up to ~1 PeV in order to understand the cosmic ray acceleration and propagation. The detector consisting of a charge detector, an imaging calorimeter, and a total absorption calorimeter, is located on the International Space Station. The thickness of the calorimeter corresponds to 30 radiation length and to ~1.3 proton interaction length. Data taking has started in October 2015 and continues stably without any serious troubles. We have taken data for more than 5 years so far. We present the latest result of proton spectrum analysis in the energy region from 50 GeV to several tenths of TeV. A fiducial geometrical factor of ~416 cm2 sr is used. The energy resolution of proton is 30-40%. The remaining background is less than 10% in 50 GeV smaller E smaller 10 TeV region. Compared to our previous result published in Physical Review Letters in 2019, statistics has been increased by more than two years. Spectral hardening in E=1-10 TeV region is then confirmed with higher statistics. We will newly discuss spectral softening above 10 TeV as well as the proton to helium spectrum ratio.'

Authors: Kazuyoshi Kobayashi | Pier Simone Marrocchesi | for the CALET Collaboration
Collaboration: CALET

Indico-ID: 390
Proceeding URL: https://pos.sissa.it/395/098