The Calorimetric Electron Telescope, (CALET) for the JEM Exposure Facility

The CALET instrument is proposed for the Japanese Experiment Module/Exposure Facility (JEM/EF) on International Space Station (ISS) to resolve the long-term puzzles in high-energy cosmic-ray physics. The ISS gives us a unique opportunity to carry out the measurements of cosmic ray electrons with a relatively heavy and large detector, and for the long exposure. The instrument will be composed of an imaging calorimeter with scintillating fibers and a total absorption calorimeter for detecting the electrons up to 10,000 GeV. The origin of high-energy electrons and the diffusion characteristics in the Galaxy will be revealed by measuring the energy spectrum of electrons and the anisotropy of arrival directions. By the excellent capability of the CALET, both of the gamma-rays over GeV and nucleus component up to 1015 eV might be investigated as additional possibilities of the observation.