The high-energy particle detector on board of the China seismo-electromagnetic satellite

The study of the Van Allen belts temporal stability is among the main objectives of the China Seismo-Electromagnetic Satellite (CSES) space mission, as well as the study of other electromagnetic disturbances with possible seismic origin. In parallel to this, the CSES mission will address issues of heliospheric and magnetospheric physics, by measuring the cosmic radiation around the Earth. The CSES satellite, developed by a Chinese-Italian collaboration, will be launched in the first half of 2017 and inserted into a circular Sun-synchronous orbit with 98° inclination and 500 km altitude. The expected lifetime is 5 years. CSES hosts several instruments on board: 2 magnetometers, an electric field detector, a plasma analyser, a Langmuir probe and a High-Energy Particle Detector (HEPD). The HEPD detector, responsibility of the Italian side of the CSES collaboration, will measure electrons (3 - 100 MeV) and protons (30 - 300 MeV) along CSES orbit. It consists of a segmented layer of plastic scintillators for the trigger and a calorimeter constituted by a tower of plastic scintillator counters and a LYSO plane. The direction of the incident particle is provided by two planes of double-side silicon micro-strip detectors placed in front of the trigger. Topic of this talk is the technical description of the HEPD and its main characteristics.