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Galactic and Solar Cosmic Rays

NSSDCA ID: 1967-073A-09

Mission Name: OGO 4
Principal Investigator:Prof. William R. Webber


This cosmic-ray telescope experiment was designed to measure the differential energy spectra of protons, helium nuclei, and heavier nuclei up to Z=10 within the energy range 50 to 2000 MeV/nucleon and at a maximum sampling rate of once per 288 ms. The telescope consisted of two detectors, a scintillator with its associated photomultiplier (PM) tube and a scintillator and a Cerenkov element sandwich with both elements optically coupled to the same PM tube. A 70-ns coincidence circuit coupled the two detectors to form the telescope. Pulses from each PM tube were pulse-height analyzed. Sampled pulse heights, the coincidence count rate, and the count rate of the first detector were telemetered. The resolution of the OGO 4 detector deteriorated at launch, probably due to partial separation of an optical interface in one element of the telescope. This resulted in a reduced efficiency for detecting protons greater than about 200 MeV, with the worst resolution near the Cerenkov threshold of 320 MeV. Otherwise, the experiment functioned as planned until October 23, 1969. NSSDC has all the useful data that exist from this investigation.

Alternate Names

  • OGO4/GalacticandSolarCosmicRays
  • Scintillation Crystal and Cerenkov Detector


  • 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
Prof. William R. WebberPrincipal InvestigatorUniversity of New
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