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Electrons and Hydrogen and Helium Isotopes

NSSDCA ID: 1973-078A-06

Mission Name: IMP-J
Principal Investigator:Prof. Edward C. Stone, Jr.


This experiment was designed to measure the differential energy spectra of the isotopes of hydrogen through oxygen from 2 to 40 MeV/nucleon, and of electrons from 0.2 to 5 MeV. The instrument consisted of a stack of 11 fully depleted silicon solid-state detectors surrounded by a plastic scintillator anticoincidence cup. The outer two solid-state detectors were annular, permitting measurements in both narrow-geometry (typical geometrical factor was 0.2 sq cm-sr) and wide-geometry (typical geometric factor was 1.5 sq cm-sr) coincidence modes. Anisotropy data (45-deg angular and 20-s temporal resolution) were obtained. For further details, see R. A. Mewaldt and E. C. Stone, Astrophys. J., v. 205, p. 93, 1976.

Alternate Names

  • IMP-J/ElectronsandHydrogenandHeliumIsotopes


  • Space Physics: Magnetospheric Studies
  • Space Physics: Heliospheric Studies

Additional Information

Questions and comments about this experiment can be directed to: Coordinated Request and User Support Office



NameRoleOriginal AffiliationE-mail
Dr. William E. AlthouseGeneral ContactCalifornia Institute of
Dr. Rochus E. VogtOther InvestigatorCalifornia Institute of
Dr. Richard A. MewaldtOther InvestigatorCalifornia Institute of
Prof. Edward C. Stone, Jr.Principal InvestigatorCalifornia Institute of
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