Study of the performance of the HERD calorimeter for the measurement of the electron flux

The measurement of the cosmic-ray electron+positron flux at high energy is a key tool to look for possible astrophysical sources of high-energy electrons/positrons and indirect signals of dark matter. The current measurement of the electron+positron flux is limited to an energy of about 7 TeV, and it is insufficient to reach a clear conclusion on these two possible contributions. The limitation in energy is mainly due to the geometric acceptance of the current in-orbit space experiments. Thanks to the larger geometric factor, the future space experiment HERD will have a larger geometric factor and will extend the flux measurement up to tens of TeV. In this paper, using simulations, we study the performance of the calorimeter of the HERD experiment for the electron+positron flux measurement, demonstrating its capability to extend it up to 15 TeV and above.