Measurements of heavy nuclei with the CALET experiment

Abstract

The CALorimetric Electron Telescope, CALET, was installed on the International Space Station in August 2015 and it has been collecting data since October 2015. Direct measurements of the high energy spectra of individual cosmic ray nuclei and of the energy dependence of secondary-to-primary abundance ratios are important for an understanding of the acceleration and propagation of cosmic rays in the galaxy. CALET is able to identify cosmic ray nuclei with individual element resolution and measure their energies in the range from a few tens of GeV to the PeV scale. The instrument consists of two layers of segmented plastic scintillators to measure the particle charge, from Z=1 to 40, a 3 radiation length thick tungsten-scintillating fiber imaging calorimeter, and a 27 radiation length thick PWO calorimeter. In this paper, the capability of charge identification and first results for heavy nuclei (Z>8) up to iron with CALET are presented.