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Medium Energy Particles Instrument - distrib. fns., p > 24 keV, e > 20 keV

NSSDCA ID: 1977-102B-07

Mission Name: ISEE 2
Principal Investigator:Dr. Ehrhard Keppler


This experiment was designed to identify and to study plasma instabilities responsible for acceleration, source and loss mechanisms, and boundary and interface phenomena throughout the orbital range of the mother/daughter satellites. A proton telescope and an electron spectrometer were flown on each spacecraft to measure detailed energy spectra and angular distributions. These detectors used silicon, surface-barrier, totally depleted, solid-state devices of various thicknesses, areas, and configurations. Protons in 5 directions and 12 energy channels between 20 keV and 2 MeV and electrons in 5 directions and 12 energy channels between 20 keV and 300 keV (to 1.2 MeV for the 90-deg direction) were measured. Data were accumulated in up to 32 sectors per spin.

Alternate Names

  • MEPI

Facts in Brief

Mass: 4.3 kg
Power (avg): 5.5 W


  • Space Physics: Magnetospheric Studies

Additional Information

Questions and comments about this experiment can be directed to: Dr. H. Kent Hills



NameRoleOriginal AffiliationE-mail
Dr. Berend WilkenOther InvestigatorMax-Planck-Institut fur Aeronomie
Dr. Donald J. WilliamsOther InvestigatorApplied Physics
Dr. Carl O. BostromOther InvestigatorApplied Physics Laboratory
Prof. Gerd H. WibberenzOther InvestigatorUniversitat
Prof. Theodore Allan FritzOther InvestigatorLos Alamos National
Dr. Ehrhard KepplerPrincipal InvestigatorMax-Planck-Institut fur

Selected References

  • Williams, D. J., et al., ISEE 1 and 2 medium energy particles experiment, IEEE Trans. Geosci. Electron., GE-16, No. 3, 270-280, doi:10.1109/TGE.1978.294561, July 1978.
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