Speaker
Description
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<E<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.
Keywords
proton; helium; CALET
| Subcategory | Experimental Results |
|---|---|
| Collaboration | CALET |
