High-energy astroparticle physics with CALET
The CALorimetric Electron Telescope (CALET) will be installed on the Exposure Facility of the Japanese Experiment Module (JEM-EF) on the International Space Station (ISS) in 2014 where it will measure the cosmic-ray fluxes for five years. Its main scientific goals are to search for dark matter, investigate the mechanism of cosmic-ray acceleration and propagation in the Galaxy and discover possible astrophysical sources of high-energy electrons nearby the Earth. The instrument, under construction, consists of two layers of segmented plastic scintillators for the cosmic-ray charge identification (CHD), a 3 X-thick tungsten-scintillating fiber imaging calorimeter (IMC) and a 27 X-thick lead-tungstate calorimeter (TASC). The CHD can provide single-element separation in the interval of atomic number Z from 1 to 40, while IMC and TASC can measure the energy of cosmic-ray particles with excellent resolution in the range from few GeV up to several hundreds of TeV. Moreover, IMC and TASC provide the longitudinal and lateral development of the shower, a key issue for good electron/hadron discrimination. In this paper, we will review the status of the mission, the instrument configuration and its expected performance, and the CALET capability to measure the different components of the cosmic radiation.
Dept. of Physics, University of Siena, Via Roma 56, 53100 Siena, Italy
on behalf of the CALET collaboration
CALET (CALorimetric Electron Telescope) is a space-based detector
developed by a Japanese led international collaboration
to directly measure the high-energy cosmic radiation on the
International Space Station (ISS).
CALET is scheduled to be launched in 2014 by the Japanese rocket
HTV (H-IIA Transfer Vehicle) and
robotically installed on the Japanese Experiment Module Exposure Facility (JEM-EF) on ISS.
The CALET mission will address many of the outstanding questions of High-Energy Astrophysics, such as the origin of cosmic rays, the mechanism of CR acceleration and galactic propagation, the existence of dark matter and nearby CR sources, by the observations of CR electrons, rays and nuclei in a wide energy window from few GeV up to the TeV region [CALET-GOALS, CALET-DM].
2 The CALET instrument and its performance
The CALET instrument consists of a Total AbSorption Calorimeter (TASC),
a finely segmented pre-shower IMaging Calorimeter (IMC),
and a CHarge Detector (CHD) (Fig. LABEL:fig1).