The Energetic Electron Spectrometer (EES) is one of the core scientific instruments aboard Macau Science Satellite #1 (MSS-1). It measures the energetic electron flux among 50keV~2.0MeV with high temporal, angular and energy resolution. Its main objective is to monitor the typical charged particle radiation characteristics in the MSS-1’s orbit and the process of their occurrence and development, to provide highly accurate energetic electron data for space physics research and space environment modeling.

EES is composed of two detectors, mid-energy electron detector and high-energy electron detector. The mid-energy electron detector utilizes pin-hole imaging technique and can measure 50-600 keV electrons from 9 directions simultaneously, therefore achieving high-resolution pitch angle distribution of energetic electrons in AoKe-1’s orbit. The high-energy electron detector utilizes ΔE/E detector telescope technique with multi-layer silicon detectors and can measure the energetic electron spectra from 0.3 to 2.0 MeV.