BackForwardInstrument:  LEP 

Instrument details
Acronym LEP
Full name Low Energy Particles Experiment
Purpose To study the dynamics of the magnetotail plasmas, plasma circulation and its variability in response to fluctuations in the solar wind and in the interplanetary magnetic field
Short description Assemblage of three sensors, to measure: the 3-D velocity distributions of hot plasma in the magnetosphere (electrons in the energy range 6-36 eV, positive ions in the range 0.007-42 keV/Q); the 3-D velocity distributions of solar wind ions in the energy range 0.1-8 keV/Q; ion mass spectrometry for 3-D determinations of the ion composition in the energy range 0-25 keV/Q
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 to 2022
Last update: 2021-12-16
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
WIGOS Subcomponents
  • Subcomponent 2
  • Magnetospheric energetic particles and magnetometers
  • Electron sensor [cross magnetosphere]
  • Proton sensor [cross magnetosphere]
  • Alpha-particle sensor [cross magnetosphere]
  • Heavy ion sensor [cross magnetosphere]
  • Subcomponent 3
  • Neutral and Ion Mass Spectrometer
  • Heavy ions mass spectrometer [from LEO and HEO]
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
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
Note: * Primary mission objective.
VariableRelevance for measuring this variableOperational limitationsExplanation
Electron differential directional flux*2 - very highNo specific limitation.Magnetosphere, low energy (up to 40 keV)
Proton differential directional flux*2 - very highNo specific limitation.Magnetosphere, low and medium energy (up to 1000 keV)
Alpha particles differential directional flux*4 - fairNo specific limitation.Cross-magnetosphere. Low-medium energy range (<10 up to 100 MeV/n)
Heavy ion flux energy and mass spectrum*2 - very highNo specific limitation.Cross-magnetosphere. Low-medium energy range (<10 up to 100 MeV/n)
Heavy ion angular flux energy and mass spectrum*2 - very highNo specific limitation.Cross-magnetosphere. Low-medium energy range (<10 up to 100 MeV/n)