Monte Carlo Simulation of the HERO Orbital Detector Calorimeter

The High-Energy Ray Observatory (HERO) is a space-based experiment designed to measure the spectrum and composition of cosmic rays using an ionization calorimeter. The instrument’s effective geometric factor is at least 12 m2·sr for protons and 16 m2·sr or more for nuclei and electrons. Over an exposure period of approximately 5 to 7 years, the mission will enable high-resolution, element-by-element measurements of cosmic ray spectra in the energy range of 1012 to 1016 eV per particle. A Monte Carlo simulation of the calorimeter—based on a scintillation detector with and without boron additives—was carried out using the GEANT4 software package. In this study, we examine the impact of boron additives in scintillator materials on energy resolution and their potential for discriminating between electromagnetic and hadronic components of cosmic rays. The primary objectives are to demonstrate that boron does not degrade detector characteristics and that it enables an additional timing-based method for cosmic-ray component rejection. The planned launch of the orbital experiment is scheduled for no earlier than 2029.