Chemical Meters/Analyzers
SOPA
The The Synchronous Orbit Particle Analyzer (SOPA) instrument is designed to provide high spatial, high-resolution energetic particle measurements at geo-synchronous orbit on spinning satellites. As such it monitors electrons, protons, helium, carbon, nitrogen, and oxygen ions individually and all particles with Z > sulfur and all particles with Z > strontium above certain energies. Finally, the SOPA E by dE/dx capability is exploited to provide dual parameter pulse height analysis (PHA). This feature extends the ion coverage, in principal, to all ions. The SOPA instrument, because it collects many samples of the surrounding particle populations (64 per spin period), can be used to determine the symmetry axis of the distribution thus providing the magnetic field orientation. The reader is referred to Belian, et al., 1992, for further information. The instrument consists of three solid-state detector telescopes (T1, T2 and T3) that accept particles from three different directions relative to the spacecraft spin axis. Each telescope consists of a thin, 4 ?m, 10 mm2 front detector followed by a thick, 3000 ?m, 25 mm2 back detector. A collimator, with 11? (full width) field of view fronts the detector stack. High and low Z passive shielding completely surround the active solid-state detectors providing protection from side penetrating particles. The shielding is sized to stop 50% of the 6 MeV electrons and 65 MeV protons incident normal to the shielding surface. Additional information available at "http://leadbelly.lanl.gov/psm/dickb.html" [Summary provided by Leadbelly]