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Geocoronal Lyman-Alpha Scattering

NSSDCA ID: 1964-054A-10

Mission Name: OGO 1
Principal Investigator:Dr. Phillip W. Mange


The objective of this experiment was to measure the intensity of hydrogen Lyman-alpha radiation (1216 A) scattered by neutral hydrogen at 5 to 20 earth radii. This wavelength is the fundamental resonance line of neutral atomic hydrogen, and these intensity measurements, therefore, provided a measure of the density of neutral hydrogen in the hydrogen geocorona. The instrumentation consisted of four ion chambers mounted on the antiearth door of OGO 1. Each ion chamber was filled with nitric oxide gas and had lithium fluoride windows. The ion chambers were sensitive in the 1050- to 1350-band. The instrumentation faced the sun steadily for more than 4 months before viewing the sun-free sky, causing detector degradation. The maximum intensities observed were lower than those measured by the OGO 3 ion chambers by a factor of more than 30. This difference has been attributed primarily to the spurious response of the damaged detectors to radiation belt particles. The data obtained from the experiment were not a measure of the Lyman-alpha intensity because of the detector degradation. Data from this investigation no longer exist.

Alternate Names

  • OGO1/GeocoronalLyman-AlphaScattering


  • Space Physics: Ionospheric Studies

Additional Information

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



NameRoleOriginal AffiliationE-mail
Dr. Phillip W. MangePrincipal InvestigatorUS Naval Research Laboratory
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