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Solar X-Ray Emissions

NSSDCA ID: 1967-073A-21

Mission Name: OGO 4
Principal Investigator:Mr. Robert W. Kreplin


This experiment was composed of four ionization chambers that were sensitive in nominal 0.5-3 A, 1-8 A, 8-16 A (or 8-20 A), and 44-60 A passbands. The detectors were mounted in the solar-oriented experiment package (SOEP) of the spacecraft and were pointed continuously at the sun. The currents generated in the ionization chambers were amplified by linear electrometers, three of which changed ranges automatically to provide the appropriate sensitivity for observations during both intense solar flares and solar quiet periods. The outputs from the electrometers were digitized and either transmitted directly to the ground or stored in the spacecraft tape recorders for later transmission. The worst time resolution, obtained with the spacecraft multiplexer operating at 4 kbs, was 4.6 s for the 8-16 A and 44-60 A detectors. The time resolution was considerably better for the 0.5-8 A detectors. The 44-60 A detector failed in November 1967, but the other three detectors produced useful data until the spacecraft tape recorder was disabled in January 1969. For results, see R. W. Kreplin et al., "Measurements of solar X-ray emission from the OGO 4 spacecraft," Solar Flares and Space Research, pp. 121-130, North Holland Publ. Co., Amsterdam, The Netherlands, 1969. NSSDC has all the useful data that exist from this investigation.

Alternate Names

  • OGO4/SolarX-RayEmissions
  • Solar X-Ray Flux Measurement

Funding Agency

  • NASA-Office of Space Science Applications (United States)


  • Solar Physics: X-Ray

Additional Information

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



NameRoleOriginal AffiliationE-mail
Dr. Talbot A. ChubbOther InvestigatorUS Naval Research Laboratory
Dr. Herbert D. FriedmanOther InvestigatorUS Naval Research Laboratory
Mr. Robert W. KreplinPrincipal InvestigatorUS Naval Research
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