Low energy plasma analyzer

The low energy plasma analyzer (LEPA) that operates in a direct wave-particle mode in which waves (below 30 kHz), measured by separate onboard electric field and wave experiments, and LEPA signals that are directly cross-correlated, is described. LEPA was developed for the Combined Release and Radiation Effects Satellite (CRRES). LEPA is capable of determining the three-dimensional distribution function of electrons and positive ions in this energy range while simultaneously determining the location in the distribution function and the frequency at which coherent wave-particle interactions may be occurring. The LEPA measurement system uses tri-quadrispherical electrostatic analyzers with microchannel plate detectors. >