Performance of the ISS-CREAM calorimeter in a calibration beam test

The Cosmic Ray Energetics And Mass experiment for the International Space Station (ISS-CREAM) was installed on the ISS to measure high-energy cosmic-ray elemental spectra for the charge range Z = 1 to 26. The ISS-CREAM instrument includes a tungsten scintillating-fiber calorimeter preceded by a carbon target for energy measurements. The carbon target induces hadronic interactions, and showers of sec-ondary particles develop in the calorimeter. The energy deposition in the calorimeter is proportional to the particle energy. As a predecessor to ISS-CREAM, the balloon-borne CREAM instrument was successfully flown seven times over Antarctica for a cumulative exposure of 191 days. The CREAM calorimeter demonstrated its capabil-ity to measure energies of cosmic-ray particles, and the ISS-CREAM calorimeter is expected to have a similar performance. Before the launch, an engineering-unit calorimeter was shipped to CERN for cali-bration and performance tests. This beam test included position, energy, and angle scans of electron and pion beams together with a high-voltage scan for calibration and characterization. Additionally, an atten-uation effect in the scintillating fibers was studied. In this paper, beam test results, including corrections for the attenuation effect, are presented. (c) 2021 Elsevier B.V. All rights reserved.