Summary Ion Data: R-Files, Format4

Description

This data set contains averaged values of ion composition data, excluding periods when the instrument was dedicated to solar wind observations. The data are in digital form plus supplemental hard copy plots (Dataset 77-102A-12G). Analysis and plot programs accompany the data. Each file covers one spacecraft orbital revolution, approximately 57 h and 20 min. For survey purposes each orbit was divided into time intervals appropriate for display on one summary plot. The length of each interval (ranging from 30 min to 3 h) was chosen to be roughly proportional to the inverse of the spacecraft velocity. Within each interval, the ion count rates were averaged over time in various bins according to energy, species, and direction of motion of the ion. Programs are provided that generate plots as follows: (1) mass spectra for given energy; (2) differential ion flux spectra (for six directions of ion motion) vs energy per charge for masses 1 and 16; (3) the same for masses 2 and 4; and (4) number density, mean energy in the plasma frame, and magnitude and angle (in the spin plane) of the inferred drift velocity, vs time. Hard copy plots of type 4 are also provided, with data points typically at 1-3 min intervals. The programs also can generate a table of beta (ratio of ion kinetic pressure to magnetic pressure) and other parameters related to the moment calculations. The analysis and plotting programs provided are written in Fortran for VAX 11/780 and use either Versatec Versaplot V07 graphics subroutines or Precision Visuals DI-3000 graphics subroutines. In addition to the hard copy plots of type 4 above, which show one interval per plot, supplemental three-dimensional plots covering one orbit per plot are included for seven plot types: directional differential flux of H+ and O+, for both "transverse" and "parallel" directions; directional differential flux for He+ and He++, averaged over all pitch angles; and background rate, normalized to appear as a flux spectrum. An extensive user's guide for the data set was provided by the investigator.