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32-Sec Energetic Ions Sector Counts and Average Intensities, G-Z Comet Encounter


Availability: At NSSDC, Ready for Offline Distribution (or Staging if Digital)

Time span: 1985-09-10 to 1992-09-14


These data from the Energetic Proton experiment on ICE, also known as the Energetic Particle Anisotropy Spectrometer (EPAS), cover the the comet Giacobini-Zinner encounter period and consist of 3-dimensional distributions of energetic particles in 5 energy channels (from 65 keV to 480 keV), 8 azimuthal sectors and 3 polar angles. A complete 3-dimensional distribution was measured at 32-second intervals during the main encounter phase, later changing to 64 seconds. Directional averaged ion intensities in the 5 energy channels are determined assuming water-group ions, and the ion streaming direction is derived from a spherical harmonic fit to the sectored data in channel E1. The data were provided in ASCII format, and the parameters in the data files are: the date and time; the telescope number, channel number, number of spins, and counts in sectors 1 to 8; the direction-averaged ion intensities (using 3 telescopes x 8 sectors) for channels E1 to E5 in units of counts/(cm^2-sec-ster-keV), assuming water group ions, and the channel E1 ion streaming direction relative to the spacecraft. The ion streaming direction is derived from the first-order term of a third-order spherical harmonic fit to the log of the sectored data in channel E1. Occasionally, an erroneously large number of "counts" is recorded in a sector. An attempt has been made to remove these bad data points, but a few may still remain. This data set does not contain any spacecraft position information. Trajectory data for the ICE spacecraft relative to the comet are archived separately as data set 78-079A-00E. Data from the following other experiments on ICE for part or all of the same period are also archived: Solar Wind Plasma (78-079A-01R), Vector Helium Magnetometer (78-079A-02N), Low-Energy Cosmic Rays (78-079A-03E), Plasma Wave (78-079A-07D), and Radio Mapping (78-079A-10D).

Alternate Names

  • Energetic Ions (EPAS), G-Z Encntr


  • Space Physics: Zodiacal Light/Interplanet Dust


  • 78-079A-08F

Additional Information



Questions and comments about this data collection can be directed to: Dr. H. Kent Hills



NameRoleOriginal AffiliationE-mail
Dr. Robert J. HyndsData ProviderImperial
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