NSSDCA ID: 1963-046A-04
Mission Name: IMP-AThis experiment consisted of two detector systems. The first was a dE/dx vs E telescope with thin and thick CsI scintillators (one each) and an anticoincidence plastic scintillation counter. The telescope axis was normal to the spacecraft spin axis. Counts of particles penetrating the thin CsI scintillator and stopping in the thick CsI scintillator were accumulated during one 39.36-s interval every 5.46 min. The relative contribution to the count rate of various species (electrons between 3 and 12 MeV, ions with charge = 1 or 2, atomic mass = 1, 2, 3 or 4, and energy between 18.7 and 81.6 MeV/nucleon) and energy spectral information were determined by 512-channel pulse-height analysis performed simultaneously on the output of both CsI scintillators six times every 5.46 min. The second detector system consisted of two Geiger-Mueller tube telescopes oriented parallel to and perpendicular to the spacecraft spin axis. Each telescope consisted of two colinear GM tubes. The parallel and perpendicular telescopes measured, respectively, (1) the sum of counts due to protons above 70 MeV and electrons above 6.5 MeV and (2) the sum of counts due to protons above 65 MeV and electrons above 6 MeV. Counts registered in any one of the four GM tubes were also accumulated. These omnidirectional counts were due to protons above 50 MeV plus electrons above 4 MeV. The parallel, perpendicular, and omnidirectional count rates were obtained for one 40-s accumulation interval during successive normal 81.9-s telemetry sequences. Thus, any one count rate was measured for 40 s once each 5.46 min. Both detector systems worked well from launch until May 26, 1964. For further details, see McDonald et al., J. Geophys. Res., v. 67, p. 2119, 1962, or Balasubrahmanyan et al., J. Geophys. Res., v. 70, p. 2005, 1965.
Questions and comments about this experiment can be directed to: Coordinated Request and User Support Office
Name | Role | Original Affiliation | |
---|---|---|---|
Dr. Frank B. McDonald | Principal Investigator | NASA Goddard Space Flight Center |