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Low Energy Cosmic Ray Experiment

NSSDCA ID: 1977-102A-05

Mission Name: ISEE 1
Principal Investigator:Dr. Dieter K. Hovestadt


This instrument, carried on both ISEE 1 and ISEE 3, was designed to measure solar, interplanetary, and magnetospheric energetic ions in numerous bands within the energy range 2 keV/charge to 80 MeV/nucleon, and electrons in four contiguous bands from 75 to 1300 keV. At the lower energies, charge states of heavy ions in the high-speed ( > 500 km/s) solar wind were determined. In the range 0.3 to 80 MeV/nucleon, the energy spectra, anisotropies, and composition of energetic ions were determined. In the limited range 0.4 to 6 MeV/nucleon, simultaneous determination of ionic and nuclear charge was possible. The instrument consisted of three different sensor systems. ULECA (ultralow-energy charge analyzer) was an electrostatic analyzer with solid-state detectors. Its energy range was approximately 3 to 560 keV/charge. ULEWAT (ultralow-energy wide-angle telescope) was a double dE/dx vs E, thin-window, flow-through proportional counter/solid-state detector telescope covering the range 0.2 to 80 MeV/nucleon (Fe). ULEZEQ (ultralow-energy Z, E, and Q) was a combination of an electrostatic analyzer and a dE/dx vs E system with a thin-window proportional counter and a position-sensitive solid-state detector. The energy range was 0.4 to 6 MeV/nucleon. Data could be obtained in 45-deg sectors.

Alternate Names

  • HOM
  • ISEE1/LowEnergyCosmicRayExperiment
  • Low Energy Cosmic Ray Composition
  • Low-Energy Cosmic Rays, 2 keV/charge to 80 MeV/nuc (Ions); 75-1300 keV(electrons)
  • Nuclear and Ionic Charge Distribution Particle Experiment

Facts in Brief

Mass: 12.9 kg
Power (avg): 6 W

Funding Agency

  • European Space Agency (International)


  • Space Physics: Heliospheric Studies

Additional Information

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



NameRoleOriginal AffiliationE-mail
Dr. Charles Y. FanOther InvestigatorUniversity of Arizona
Prof. George GloecklerOther InvestigatorUniversity of
Dr. Lennard A. FiskOther InvestigatorUniversity of New
Dr. Manfred ScholerOther InvestigatorMax-Planck-Institut fur Extraterrestrische
Dr. Joseph J. O'GallagherOther InvestigatorUniversity of
Dr. Dieter K. HovestadtPrincipal InvestigatorMax-Planck-Institut fur Extraterrestrische Physik

Selected References

  • Hovestadt, D., et al., The nuclear and ionic charge distribution particle experiments on the ISEE-1 and ISEE-C spacecraft, IEEE Trans. Geosci. Electron., GE-16, No. 3, 166-175, doi:10.1109/TGE.1978.294540, July 1978.
  • Ipavich, F. M., et al., Composition and energy spectra of low energy ions observed upstream of the earth's bow shock on ISEE-1, in Proc. 16th Intern. Cosmic Ray Conf., Vol. 3, 140-144, 1979.
  • Ipavich, F. M., et al., Initial observations of low energy charged particles near the earth's bow shock on ISEE-1, Space Sci. Rev., 23, No. 1, 93-101, doi:10.1007/BF00174113, Mar. 1979.
  • Ipavich, F. M., et al., A statistical survey of ions observed upstream of the earth's bow shock: energy spectra, composition, and spatial variation, J. Geophys. Res., 86, No. A6, 4337-4342, doi:10.1029/JA086iA06p04337, June 1981.
  • Scholer, M., et al., Upstream energetic ions and electrons: Bow shock-associated or magnetospheric origin?, J. Geophys. Res., 86, No. A11, 9040-9046, doi:10.1029/JA086iA11p09040, Oct. 1981.
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