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Cosmic-Ray Energy vs Energy Loss

NSSDCA ID: 1967-051A-10

Mission Name: IMP-F
Principal Investigator:Dr. Frank B. McDonald


This experiment used a dE/dx vs E telescope with thin and thick CsI scintillators (one each) and an anticoincidence plastic scintillation counter. The telescope axis was parallel to the spacecraft spin axis. Counts of particles penetrating the thin CsI scintillator and stopping in the thick CsI scintillator were accumulated for a 4.48-s interval twice every 2.73 min. The relative contribution to the count rate of various species (electrons between 2.7 and 21.5 MeV, nuclei with charge 1 and 2, atomic mass 1, 2, 3, and 4, and energy between 18.7 and 81.6 MeV/nucleon) and energy spectral information were determined by 1024-channel pulse-height analysis performed simultaneously on the output of both CsI scintillators 16 times every 2.73 min. Counts of electrons between 0.3 and 0.9 MeV stopping in the thin scintillator were also obtained once each 2.73 min. Except as noted above, the experiment performed well from launch until May 3, 1969 (spacecraft reentry date).

Alternate Names

  • IMP-F/Cosmic-RayEnergyvsEnergyLoss


  • 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. George H. LudwigOther InvestigatorNOAA Environmental Research Laboratories
Dr. Frank B. McDonaldPrincipal InvestigatorNASA Goddard Space Flight Center
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