As its name implies, the Cosmic Ray Subsystem (CRS) was designed for cosmic ray studies [STONEETAL1977B]. It consists of two high Energy Telescopes (HET), four Low Energy Telescopes (LET) and The Electron Telescope (TET). The detectors have large geometric factors (~ 0.48 to 8 cm^2 ster) and long electronic time constants (~ 24 [micro]sec) for low power consumption and good stability. Normally, the data are primarily derived from comprehensive ([Delta]E, [Delta]Eand E) pulse- height information about individual events.
Because of the high particle fluxes encountered at Jupiter and Saturn, greater reliance had to be placed on counting rates in single detectors and various coincidence rates. In interplanetary space, guard counters are placed in anticoincidence with the primary detectors to reduce the background from high-energy particles penetrating through the sides of the telescopes. These guard counters were turned off in the Jovian magnetosphere when the accidental anticoincidence rate became high enough to block a substantial fraction of the desired counts. Fortunately, under these conditions the spectra were sufficiently soft that the background, due topenetrating particles, was small.