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Cosmic-Ray Spectra and Fluxes

NSSDCA ID: 1964-054A-18

Mission Name: OGO 1
Principal Investigator:Dr. John A. Simpson


Three solid-state particle telescopes were used to measure the intensity and energy distribution of cosmic rays. A dE/dx vs E telescope resolved the nuclear composition of cosmic rays in the energy range from 22 to 103 MeV/nucleon (charge resolution ranged through Z=26, energy per nucleon intervals approximately proportional to Z squared/A). A dE/dx vs range telescope (proton-alpha telescope) detected protons and alpha particles in the energy range from 1.4 to 33 MeV/nucleon, and a single-element low-energy proton telescope (OPEP telescope) was primarily sensitive to protons in the energy range from 1.4 to 3.7 MeV. The composition and proton-alpha telescopes were oriented parallel to the spacecraft Z axis. Pulse-height information was obtained from the composition telescope using one 256-channel and two 512-channel pulse-height analyzers. This allowed pulse-height analysis of particles in four energy intervals, for protons 5 to 11 MeV, 11 to 22 MeV, 22 to 103 MeV, and greater than 103 MeV. Pulse-height information sent back from the proton-alpha telescope allowed pulse-height analysis of particles in two energy ranges, protons 1.4 to 8.6 MeV and 8.6 to 33 MeV. This transmission used one 256-channel pulse-height analyze while count rate information was sent back from all three telescopes. The time resolution ranged from about one measurement per 0.02 s to about one measurement per 147 s depending on the counting mode and the telemetry bit rate. The spacecraft unintended initial spin period about the Z axis was about 12 s. For further details, see Comstock, G. M., et al., Ap. J., v. 146, p. 51, 1966.

Alternate Names

  • OGO 1,Cosmic Ray Spectra and Fluxes (A-07)
  • OGO1/Cosmic-RaySpectraandFluxes

Facts in Brief

Mass: 10 kg
Power (avg): 1.7 W
Bit rate (avg): 64 kbps

Funding Agency

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


  • 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
Dr. Gordon LentzGeneral ContactUniversity of Chicago
Dr. Charles Y. FanOther InvestigatorUniversity of Arizona
Dr. John A. SimpsonPrincipal InvestigatorUniversity of Chicago
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