Performance Of The Calet Calorimeter By Accelerator Beam Test

We are developing the CALET (CALorimetric Electron Telescope) instrument for observing high energy electrons and gamma rays on ISS. For confirming the CALET capability expected by simulations, we made a small model of CALET with a size of 2/3 in thickness and had the experimental tests by using beams available in CERN. The beams used are 50GeV, 100GeV electrons and 150 GeV protons. The energy resolution is sigma/E = 4.0 +/- 0.1% and 2.25 +/- 0.04% for 50GeV and 100GeV electrons, respectively. About 97.3% of protons can be rejected by shower image, while approximately 96.8% of electrons are correctly identified. The performance of the model was also investigated by Monte Carlo simulation to compare with the results by beam tests. We confirmed good consistency between simulation and the beam test.