Ion identification with the Plastic Scintillator Detector for the High Energy cosmic-Radiation Detection (HERD) experiment

The High Energy Cosmic Radiation Detection (HERD) facility onboard the future China’s Space Station (CSS) will provide high quality data on charged cosmic rays and gamma rays reaching the measured range from few GeV to PeV energies. Because of this capability, HERD experiment would give a valuable contribution in several scientific topics as dark matter searches, study of cosmic ray chemical composition and high energy gamma-ray observations. HERD will be equipped with a deep 3D cubic calorimeter surrounded by a microstrip Si tracker detector. The entire instrument will be surrounded by a plastic scintillator detector (PSD). The PSD will be used to discriminate charged from neutral particles in order to correctly identify gamma-rays and nuclei. One configuration proposed and studied for the HERD PSD detector the geometry of scintillator segmented in tiles coupled to Silicon Photomultipliers (SiPMs). SiPMs provide similar or even better performances to the standard photomultiplier tubes (PMTs) with lower power consumption and cost benefits. In 2018, beam test campaigns were performed at CERN SPS with ion beam to study the scintillator response with a SiPM-based readout and to test the capability of the PSD to discriminate the ion charges. The results will be presented.