High-Energy Particle Detector (HEPD)

The High-Energy Particle Detector (HEPD), developed by the Italian Collaboration, detects electrons, protons and light nuclei. The main objective is to measure the increase of the electron and proton fluxes due to short-time perturbations of the radiation belts caused by solar, terrestrial and anthropic phenomena. The energy range explored is  3 - 100 MeV for electrons and 30 - 200 MeV for protons. 

The instrument consists of several detectors. Two planes of double-side silicon microstrip sensors placed on the top of the instrument provide the direction of the incident particle. Just below, two layers of plastic scintillators, one thin segmented, give the trigger; they are followed by a calorimeter, constituted by other 16 scintillators and a layer of LYSO sensors. A scintillator veto system completes the instrument. The power supply and electronics are inserted in a box placed at one side of the detector. The HEPD is contained in an aluminum-honeycomb box. 

Four different models have been realized and fully tested: Electrical Model (EM), Structural and Thermal Model (STM)Qualification Model (QM) and Flight Model (FM). 


HEPD-FM Tests on CSES Satellite

The HEPD Flight Model was shipped to China on December 16th, 2016 and delivered to DFH Satellite Co, Ltd in Beijing on December 30th, 2016.

In January 2017, the HEPD-FM stand-alone functionality  at satellite level (acquisition, calibration, configuration changes, RS422 max speed test) was successfully tested with its EGSE (Electrical Ground Support Equipment). Telemetry transmission to OBDH sustem successfully tested and data content verified. GPS broadcst data transmission to HEPD successfully tested (GPS data along CSES orbit generated by GNSS simulator).

Furthermore, at the end of January EMC test and in February vibration test were performed successfully.

In February and April 2017, random vibration and thermal-vacuum tests were performed on the HEPD-FM, respectively, while magnetic cleanliness and aging tests were accomplished in May. At the end of December 2017, the satellite will be transfer to the launch site, Jiuquan Satellite Launch Center in the Gobi desert (Inner Mongolia), for the pre-launch test activities.

The CSES satellite launch has been launched on February 2, 2018. HEPD Health Check has been successfully concluded.



 HEPD-FM on CSES Satellite


 Main parameters of HEPD