Gamma-Ray Burst Monitor for the CALET Mission

Abstract

A gamma-ray burst monitor fot the CALorimetric Electron Telescope (CALET) is under development. The aim of the CALET GRB Monitor (CALET-GBM) is to obtain a wide-band energy spectrum of GRB over an unprecedented nine decades in energy (from several keV to a few TeV) together with the CALET Imaging Calorimeter (IMC) and the Total Absorption Calorimeter (TASC). The GBM is under designing so as to have a sensitivity from several keV to 20 MeV. Furthermore our undergoing plan is to use six LaBr 3 (Ce) crystals from several keV to about 1 MeV measurement (one BGO for higher energy), in which light yield is about twice as large as that of NaI(Tl). LaBr 3 (Ce) is very attractive material, but this crystal has not been used yet as a detector for long exposure in space. Therefore its radiation hardness and proton induced background due to incoming protons are not fully understood. To evaluate its performance in high radiation environment of ISS orbit, we carried out proton beam irradiation tests. Proton-induced rad...