The RBSP Energetic particle, Composition, and Thermal plasma (RBSP-ECT) Suite

The RBSP-ECT SOC can be found here.

The RBSP-ECT suite consists of three instruments designed to measure plasma and energetic particles in the radiation belts and inner magnetosphere. They are:


  • the Helium Oxygen Proton Electron (HOPE) plasma spectrometer
  • the Magnetic Electron Ion Spectrometer (MagEIS)
  • the Relativistic Electron Proton Telescope (REPT)

is designed to measure the in situ plasma ion and electron fluxes over 4π sr at each RBSP spacecraft within the terrestrial radiation belts. The scientific goal is to understand the underlying physical processes that govern the radiation belt structure and  dynamics. Spectral measurements for both ions and electrons are acquired over 1 eV to 50 keV in  36 log-spaced steps at an energy resolution ΔEFWHM/E ~15%. The dominant ion species (H+,  He+, and O+) of the magnetosphere are identified using foil-based time-of-flight mass (TOF)  spectrometry with channel electron multiplier (CEM) detectors. Angular measurements are derived using five polar pixels in a plane perpendicular to the spacecraft spin axis, and up to 16  azimuthal bins are acquired for each polar pixel over time as the spacecraft spins. Ion and  electron measurements are acquired on alternate spacecraft spins. HOPE incorporates several  new methods to minimize and monitor the background induced by penetrating particles in the  harsh environment of the radiation belts. The absolute efficiencies of detection are continuously  monitored, enabling precise, quantitative measurements of electron and ion fluxes and ion species  abundances throughout the mission.


is a set of four magnetic spectrometers on each spacecraft that cover three distinct energy ranges: Low, Medium, and High. Two identical Medium energy units on each spacecraft point in different directions to increase pitch angle coverage. Electrons enter the MagEIS aperture and are bent by the magnetic field through 180° with energy-dependent diameters. Electrons are additionally energy-analyzed by an array of solid state detectors to ensure extremely clean differentiation between primary electron measurements and contaminating background radiation. MagEIS measures electrons from ~20 keV to > 4 MeV. Additionally the MagEIS High spectrometer contains a solid state telescope the measures protons from ~60 keV to ~1.3 MeV and ion by composition from ~3-50 MeV/nucleon.


consists of a stack of high-performance silicon solid-state detectors in a telescope configuration, a collimation aperture, and a thick case surrounding the detector stack to shield the sensors from penetrating radiation and bremsstrahlung. The instrument points perpendicular to the spin axis of the spacecraft and measures high-energy electrons (up to ~20 MeV) with excellent sensitivity and also measures magnetospheric and solar protons to energies well above E = 100 MeV. The instrument has a large geometric factor (g = 0.2 cm2 sr) to get reasonable count rates (above background) at the higher energies and yet will not saturate at the lower energy ranges. There must be fast enough electronics to avert undue dead-time limitations and chance coincidence effects. The key goal for the REPT design is to measure the directional electron intensities (in the range 10-2–106 particles/cm2 s-sr-MeV) and energy spectra (ΔE/E ~ 25 %) throughout the slot and outer radiation belt region.

RBSP-ECT Science Investigation Objectives:
1)  Determine the physical processes that produce radiation belt enhancement events,
2)  Determine the dominant mechanisms for relativistic electron loss,
3)  Determine how the inner magnetospheric plasma environment controls radiation belt acceleration and loss, and
4)  Develop empirical and physical models for understanding and predicting radiation belt space weather effects

RBSP-ECT Data Products:
All products can be found at the ECT SOC
Summary Plots for HOPE, MagEIS, and REPT are available here
Digital Data Directories for HOPE, MagEIS, and REPT can instead be found here