Development of Avalanche PhotoDiode (APD) Type Electron Measurement Unit for Space Use Focused on Satellite Charging

Satellite charging causes anomalies and its effect still accounts for the main part of failure that occurs in the space environment. It is important to measure plasma particles in order to elucidate the interactions between such charging and the space environment. For this purpose, the Avalanche PhotoDiode (APD) type sensor is used to minimize instrument size and weight. The APD basically measures photons, but can also be used to measure electrons. This paper reports the performance of the APD sensor, and presents the instrument design results for flight investigation.