$B!y(BEIS electron and ion spectrometer
Electron and Ion Spectrometer (EIS) onboard Planet-B will measure the energy flux
of high enegy particles such as electrons, photons, helium ions and oxygen ions ,in the
range of 40 keV to 500 keV per charge.
An interaction of the solar wind with the upper atmosphere of Mars produces energetic
electrons and ions of a few hundreds of eV to a tens of keV. The EIS will measure these
particles and contribute to the understanding of the acceleration mechanism.