Measurement of potential aboard spacecrafts

A description is given of a system for measuring variations in body potential during a satellite experiment. The method is based on detecting the energy spectrum of the particle fluxes in the surrounding plasma. To ensure microsecond resolution, a 90-deg toroidal electrostatic analyzer is used as a sensor. The detecting element comprises two microchannel plates with a coefficient of amplification of 10 to the 7th operating in the counting mode. Since the body potential becomes positive during the operation of the electron gun, a bi-polar sweep is fed into the plates of the toroidal analyzer, thereby ensuring the detection of the energy spectrum of the proton and ion fluxes.