BackForwardInstrument:  HEP 

Instrument details
Acronym HEP
Full name High Energy Particles Experiment
Purpose To measure high energy particles traveling through the magnetosphere up to 25 MeV for electrons, 35 MeV for protons, and 210 MeV/charge for ions
Short description Assemblage of five instruments: a low-energy particle detector, a burst detector, two medium-energy Isotope detectors and a high energy Isotope detector. Energy ranges: 0.02-2.5 MeV (electrons), 0.002-35 MeV (protons), 0.004-140 MeV (alpha-particles) and 0.002-210 MeV/n (ions with Z from 3 to 26)
Background Part of a package of instruments to observe the Magnetosphere by navigating across its tail
Scanning Technique Travelling cross the Magnetosphere in a highly-elliptical orbit
Resolution N/A
Coverage / Cycle Magnetospheric volume
Mass Power Data Rate

 

Providing Agency JAXA
Instrument Maturity Flown on an R&D satellite
Utilization Period: 1992-10-02 to 2003
Last update: 2017-06-05
Detailed characteristics
Satellites this instrument is flying on

Note: a red tag indicates satellites no longer operational, a green tag indicates operational satellites, a blue tag indicates future satellites

Instrument classification
  • Solar and space environment monitors
  • Energetic particle spectrometer
Mission objectives
Primary mission objectives
  • Alpha particles differential directional flux
  • Electron differential directional flux
  • Heavy ion angular flux energy and mass spectrum
  • Heavy ion flux energy and mass spectrum
  • Proton differential directional flux
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Tentative Evaluation of Measurements

The following list indicates which measurements can typically be retrieved from this category of instrument. To see a full Gap Analysis by Variable, click on the respective variable.

Note: table can be sorted by clicking on the column headers
VariableRelevance for measuring this variableOperational limitationsExplanation
Electron differential directional flux2 - very highNo specific limitation.Magnetosphere, low, medium and high energy (up to over 400 keV)
Proton differential directional flux2 - very highNo specific limitation.Magnetosphere, low, medium and high energy (up to over 1000 keV)
Alpha particles differential directional flux4 - fairNo specific limitation.Cross-magnetosphere. Low-medium energy range (<10 up to 100 MeV/n)
Heavy ion flux energy and mass spectrum2 - very highNo specific limitation.Cross-magnetosphere. Extended energy range (<10 to >100 MeV/n)
Heavy ion angular flux energy and mass spectrum2 - very highNo specific limitation.Cross-magnetosphere. Extended energy range (<10 to >100 MeV/n)