The RIMS experiment onboard the DE-1 satellite was designed to perform energy and mass-per-charge analysis on low-energy ions (less than 50 eV) with mass/charge ranging from 1 to 40 amu/Z. RIMS significantly improved capabilities over previous retarding potential analyzer instruments (RPA) by providing ion mass/charge separation so that RPA and spin curves are obtained separately for each programmed species. These enhanced instrument capabilities, combined with the DE-1 orbit, produced a unique opportunity to investigate the variable dynamics and composition of the low-energy ion population in the near-Earth space environment.

DE-1/RIMS consists of four instrument assemblies interconnected to form one experiment. Three of the assemblies are sensor heads and one is the central electronics assembly. The three heads are labeled according to the mounting axis on the DE-1 spacecraft: Radial, +Z, and -Z. The radial sensor views perpendicular to the spacecraft spin axis, while the ąZ sensors on the ends of the spacecraft view parallel and anti-parallel to the spin axis. The central electronics assembly (CEA) provides the spacecraft interface, all data processing, command decoding, and complete timing control of the entire RIMS experiment.
Please access the mission and instrument description links above for more detailed information.
Space Plasma Physics Branch
Marshall Space Flight Center
NASA
Last Updated: September, 1998