The Energetic Particle Detector (EPD) is an instrument suite comprising different sensors that have been designed
to measure the spectra, composition, time variations, and directional distributions ofenergetic particles.
These measurements will be performed over a partly overlapping energy range encompassing a few keV to
450 MeV/n, with sufficient time, energy, angular, and mass resolution to achieve the mission science goals.
The EPD consists of the following units :
* SupraThermal Electrons and Protons (STEP).

   Designed to measure protons and electrons 
   at supra-thermal energies (between 2 and 80 keV). It employs two co-aligned sensor heads with a parallel field of view. 
   One of the sensor heads contains a permanent magnet that deflects electrons out of the nominal field of view, this is referred 
   to as magnet channel and measures all types of particles except electrons. 
   The other head measures every particle in the energy range including electrons and is called integral channel. 
   Each head contains a solid state detector divided in several pixels to achieve angular resolution. For each channel there are 
   15 pixels distributed in 3 rows and 5 columns, plus a separate pixel for measuring background.