Overview of the HERD space mission

Abstract

The High Energy cosmic Radiation Detector (HERD) is a prominent space-borne instrument to be installed on-board the Chinese Space Station (CSS) around 2027, resulting from a collaboration among Chinese and European institutions. Primary scientific goals of HERD include: precise measurements of the cosmic ray (CR) energy spectra and mass composition at energies up to few PeV, electron/positron spectra up to tens of TeV, CR anisotropy, gamma ray astronomy and transient studies, along with indirect searches for Dark Matter candidates. The detector is configured to accept incident particles from both its top and four lateral sides. Owing to its pioneering design, more than one order of magnitude increase in geometric acceptance is foreseen, with respect to previous and ongoing experiments. HERD is conceived around a deep (∼55 X 0, 3 λ I ) 3D cubic calorimeter (CALO), forming an octagonal prism. Fiber Trackers (FiTs) are instrumented on all active sides, with a Plastic Scintillator Detector (PSD) covering the calorimeter and tracker. Ultimately, a Silicon Charge Detector (SCD) envelops the above-stated sub-detectors, while a Transition Radiation Detector (TRD) is instrumented on one of its lateral faces, for energy calibration in the TeV scale. This work illustrates HERD’s latest advancements and scientific objectives along with an overview of upcoming activities.