Abstract
The standard model of shock acceleration of cosmic ray nuclei around SNR (Supernova Remnants) suggests that the acceleration limits should be around Z x 10 14 eV for nuclei with atomic number Z. But no direct observations have shown the indication of this limit even for proton spectrum so far. On the other hand, we observe the energy spectra which are modified by the propagation in the Galaxy. So it is important to understand the propagation as well as the acceleration mechanisms. Observation of various components of cosmic ray nuclei up to 10 15 eV with higher statistical accuracy is essential to understand cosmic ray physics. In such situation, the CALET (CALorimetric Electron Telescope) mission is proposed for study of high energy cosmic rays. Although CALET is originally designed for detections of electrons and gamma rays, nuclear components of primary cosmic rays, from protons to iron nucleus and more, are also observable, because it has a calorimeter which is thick enough to detect nuclear interactions and to measure the energy by calorimetric method. The energy spectra for several nuclear components and the secondary/primary ratios which will be observed by CALET mission are roughly estimated with assuming three years operation. The CALET has capability to obtain the energy spectra for each nuclear species up to 10 15 eV, and to provide the unique data for secondary/primary ratios in unexplored energy region.
