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Energetic Particle Anisotropy Spectrometer (EPAS)

NSSDC ID: 1978-079A-08
Mission Name: ISEE 3


This experiment, designated DFH, was designed to study low-energy solar proton acceleration and propagation processes in interplanetary space. The instrument measured the energy spectrum in 8 channels, and the 3-dimensional angular distribution of protons in the energy range 0.035 to 1.6 MeV with a basic time resolution of 16 s. Counts of each channel were grouped into eight 45-deg sectors. The instrument consisted of three identical telescopes mounted at 30, 60, and 135 deg relative to the spacecraft spin axis, each containing two surface-barrier detectors, a mechanical collimator, and a "broom" magnet to sweep away electrons.

Alternate Names

  • EPAS

Facts in Brief

Mass: 4.1 kg
Power (avg): 3.5 W

Funding Agency

  • European Space Agency (International)


  • Space Physics: Heliospheric Studies
  • Space Physics: Magnetospheric Studies

Additional Information

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



NameRoleOriginal AffiliationE-mail
Dr. R. M. Van Den NieuwenhofOther InvestigatorUniversity of Utrecht 
Dr. Jan J. Van RooijenOther InvestigatorUniversity of
Dr. Trevor R. SandersonGeneral ContactESA-European Space Research and Technology Centre 
Dr. Klaus Peter WenzelOther InvestigatorESA-European Space Research and Technology
Dr. Vicente DomingoOther InvestigatorESA-European Space Research and Technology
Dr. Andre BaloghOther InvestigatorImperial
Prof. Cornelis de JagerOther InvestigatorUniversity of
Dr. D. Edgar PageOther InvestigatorESA-European Space Research and Technology Centre 
Prof. Harry ElliotOther InvestigatorImperial College 
Dr. J. N. Van GilsOther InvestigatorUniversity of Utrecht 

Selected References

Balogh, A., et al., Low energy proton experiment on ISEE-C, IEEE Trans. Geosci. Electron., GE-16, No. 3, 176-180, July 1978.

Balogh, A., and T. Iversen, Digital onboard processor for directional charged particle flux measurements in space, Space Sci. Instrum., 3, 187-198, 1977.

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