Operation of the rapid scan particle spectrometer SC5 on the SCATHA satellite

The SC5 Rapid Scan Particle Spectrometer on the SCATHA satellite was designed to measure electrons and protons from 0.05 to 500 keV. Electrostatic analyzers (ESA's) are used for the 0.05 to 70 KeV range, with 8 energy bins, and solid state spectrometers (SSS's) are used for the higher energy range. Two complete detector sets view in perpendicular and parallel directions to the satellite spin axis, and a complete set of spectra is measured once per second. With a 57 second spin period, the perpendicular detector set provides pitch angle distributions with 6 degrees resolution. The SC5 instrument can also be connected to a broad-band FM channel where the output of any one detector can be viewed with 250 microsecond time resolution. The SCATHA satellite was launched on 30 January 1979, and SC5 was turned on 9 February 1979. Since then it has provided a considerable amount of particle data for an environmental atlas, and much unique data, especially from the high time resolution FM band, for electron and ion gun operations. The complete detector set has operated properly for over a year, well in excess of the design life of six months. The SC5 data analysis procedure is described, and several examples of reduced spectra and pitch angle distributions are given. Some examples of FM data from the electron gun operations are also given.