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Geiger Tube Telescope (GTT)

NSSDCA ID: 1973-019A-11

Mission Name: Pioneer 11
Principal Investigator:Prof. James A. Van Allen


This experiment used seven miniature Geiger tubes in three arrays to measure proton and electron fluxes near Jupiter and Saturn. Detector groupings were as follows: (1) a three-element (A, B, and C) differentially shielded telescope. Tube C was shielded omnidirectionally and was used for background subtraction to provide rates such as A-C (5 to 21 MeV electrons and 30 to 77.5 MeV protons) and B-C (0.55 to 21 MeV electrons and 6.6 to 77.5 MeV protons); (2) a three-element triangular array, each element responding to electrons above 31 MeV and protons above 77.5 MeV; and (3) a thin-window tube (G) with a gold-plated elbow as the entrance aperture to admit scattered electrons above 0.06 MeV while discriminating strongly against protons. For a description of the similar experiment on Pioneer 10, see J. A. Van Allen et al., J. Geophys. Res., v. 79, p. 3395, 1974. Early results are given in Science, v. 188, p. 459, 1975. Data include the interplanetary region.

Alternate Names

  • GTT
  • Jovian Charged Particles
  • Pioneer11/JovianChargedParticles
  • urn:nasa:pds:context:instrument:gtt.p11

Funding Agency

  • NASA-Office of Space Science (United States)


  • Planetary Science: Fields and Particles
  • Space Physics: Heliospheric Studies

Additional Information

Questions and comments about this experiment can be directed to: Dr. John F. Cooper



NameRoleOriginal AffiliationE-mail
Prof. James A. Van AllenPrincipal InvestigatorUniversity of Iowa
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