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Energetic Particle

NSSDCA ID: 1967-070A-02

Mission Name: Explorer 35
Principal Investigator:Prof. Kinsey A. Anderson


This experiment consisted of a 12-cm Neher-type ionization chamber and two Lionel type 205 HT Geiger-Mueller (GM) tubes. The ion chamber responded omnidirectionally to electrons above 0.7 MeV and protons above 12 MeV. Both GM tubes were mounted parallel to the spacecraft spin axis. GM tube 1 detected electrons above 45 keV that were scattered off a gold foil. The acceptance cone for these electrons had a 70-deg full-angle and an axis of symmetry that was 20 deg off the spacecraft spin axis. GM tube 2 responded to electrons and protons above 22 and 300 keV, respectively, in an acceptance cone of 70-deg full-angle centered at the spacecraft spin axis. Both GM tubes responded omnidirectionally to electrons and protons of energies above 2.5 and 50 MeV, respectively. Pulses from the ion chamber and counts from each GM tube were accumulated for 39.72 s and read out every 40.96 s. In addition, the time between the first ion chamber pulses in an accumulation period was also telemetered. This experiment performed well initially. For further details, see Anderson, J. Geophys. Res., v. 74, p. 95, 1969. NSSDC has all the useful data that now exist.

Alternate Names

  • Energetic Particle Flux
  • Explorer35/EnergeticParticle


  • 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
Mr. George H. PittOther InvestigatorUniversity of California, Berkeley
Prof. Kinsey A. AndersonPrincipal InvestigatorUniversity of California,
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