RADIOISOTOPES

The CALorimetric Electron Telescope (CALET) space experiment, which has been developed by Japan in collaboration with Italy and the United States, is a high-energy astroparticle physics mission on the International Space Station (ISS). The primary goals of the CALET mission include investigating possible nearby sources of high energy electrons, studying the details of acceleration andpropagation of galactic cosmic rays, and searching for dark matter signatures. During an expected five-year mission, the CALET experiment is measuring the flux of cosmic-ray electrons (including positrons) to 20 TeV, gamma-rays to 10 TeV and nuclei with Z=1 to 40 up to 1,000 TeV. CALET has sufficient depth, imaging capabilities and excellent energy resolution to allow for a clear separation between hadrons and electrons and between charged particles and gamma rays. Since the start of operation at the ISS from mid-October, 2015, a continuous observation has been maintained mainly by triggering high energy (>10 GeV) showers without any major interruption. The number of the triggered events is about 20 million per month, and the number will reach to nearly one billion as of mid of July, 2019. By using the data obtained, we will have a summary of the CALET observations up to the recent period.