:Dynamics Explorer 1 Retarding Ion Mass Spectrometer (RIMS)JThe Retarding Ion Mass Spectrometer (RIMS) experiment onboard the DynamicsEExplorer (DE) 1 satellite was designed to measure ion temperature andNcomposition of the thermal plasma distribution. RIMS performed energy and massLanalysis on low energy ions (<50 eV) with mass ranging from 1 to 40 amu. TheNRIMS had significantly improved capabilities over previous retarding potentialNanalyzer (RPA) instruments by providing ion mass separation to produce RPA andCspin curves for each programmed species. These enhanced instrumentJcapabilities combined with the DE 1 orbit produced a unique opportunity toGinvestigate the variable dynamics and composition of the low-energy ion0population in the near-earth space environment. MEach MAF file data record consists of 8 seconds of RIMS data (512 samples perHchannel, each sample 1/64 sec measurement), in time order with orbit andNmagnetometer data. One record is 5624 bytes in size. Studies of the RIMS dataFset should be conducted only with a thorough understanding of the RIMS=operational modes and the instrument response to these modes.5File names are of the form Dydddhhmm-hhmm.MF1_Y, with, D is at the beginning of all RIMS MAF files y is the last digit of the year! ddd is the day count of the year< hhmm_hhmm is the start and stop hour and minute of the pass& _Y indicates a compressed data file. :(NDADS Products: Dydddhhmm-hhmm.MF1_Y, DOCUMENT, SOFTWARE)(Dataset ID 81-70A-04B)