Speaker
Description
The HERD experiment is a future calorimetric space-based mission, which will be installed on the Chinese space station in 2027. The goal of HERD is to extend the direct measurements of comic rays of more than one order of magnitude in energy compared to the current measurements. Specifically, HERD will perform for the first time direct measurements at the energies of the proton and the Helium knees. HERD will also extend the electron+positron flux measurement up to tens of TeV, in order to search for spectral structures possibly related to local sources of electrons+positrons or indirect signals of dark matter.
HERD is based on an innovative calorimeter composed of about 7500 LYSO scintillating crystals assembled in a spheroidal shape to form a homogeneous, 3D, isotropic, deep and finely segmented calorimeter. The crystal readout system is based on a double photodiode with an extremely high dynamic range, specifically developed for this application.
In this talk, we discuss the innovative design of the calorimeter, and its expected performance for the measurement of the cosmic-ray electron flux: from the energy resolution of electromagnetic showers to the flux reconstruction. The study is based on simulated data, and it is validated using the data acquired during a beam test with a calorimeter prototype. The performance of both the final detector and the tested prototype is presented, highlighting the impact of the calorimeter geometry and read-out system on its performance.