Ground-based calibration and characterization of the HE detectors for Insight-HXMT

High energy X-ray telescope (HE) is one of the three instruments of Insight-HXMT (Hard X-ray Modulation Telescope) payload. The HE detector (HED) array is composed of 18 actively NaI(Tl)/CsI(Na) phoswich scintillators with a total geometric area of ∼5100cm2 and cover the energy range 20∼250 keV. In this paper we describe the on-ground detector-level calibration campaigns and present the principal instrument properties of HEDs.