A new electrostatic analyzer for investigation of velocity-space instabilities in ionospheric plasma

Velocity-space plasma instabilities are thought to be one mechanism responsible for small spatial scale, plasma turbulence in the F-region ionosphere. The authors have developed a novel high energy resolution parallel plate electrostatic analyzer designed to measure ion spectra up to 16 eV in energy over 1024 energy channels. MicroChannel plates provide 106 charge multiplication, and though it was originally designed for space plasma of a much lower density than that of the ionosphere, we have capitalized on its sensitivity to seek fine structure in the ion energy distributions. The capability to resolve such fine structure provides us with the opportunity to diagnose non-thermal distributions, which are known to be associated with velocity-space plasma instabilities. The instrument, called the Flat Plasma Spectrometer (FlaPS), is a payload on the United States Air Force Academy´s FalconSAT-3 satellite, presently operational in a 560 km, 35A???? inclination circular orbit. Though the instrument is not yet fully commissioned, all housekeeping data indicate that the instrument is functioning properly, and we have tested the instrument in a laboratory space plasma environment. With this paper, we present FlaPS observations made of a low energy, low density laboratory Xenon plasma environment for various ion angles of incidence and plasma source bias energies. Along with these results, we will present some lessons learned about the operation of the FlaPS instrument, including handling of the microchannel plates.