MPPE-MEA

Mercury Plasma Particle Experiments - Mercury Electron Analyzer (MEA)

[Fig 3 from Saito et al., 2021]

Measurement Principle

Mercury Electron Analyzer (MEA1 and MEA2) of MPPE sensors onboard Mio, measures both the 3D distribution function of electrons in the solar wind and in the magnetosphere of Mercury in order to understand the structure and plasma dynamics of Mercury’s magnetosphere, Mercury-solar wind interactions, and the solar wind at Mercury’s position. MEA consists of two top-hat type toroidal electrostatic analyzers, microchannel plates (MCPs), high-voltage power supplies and power supply units. The analyzer selects energies of electrons from 3 eV/q up to 26 keV/q depending on the operation modes.

Members

Principal Investigator
Nicolas André (IRAP, France)
Co-Investigator
Jean-André Sauvaud (IRAP, France)
Philippe Louarn (IRAP, France)
Vincent Génot (IRAP, France)
Christian Mazelle (IRAP, France)
Iannis Dandouras (IRAP, France)
Christian Jacquey (IRAP, France)
Benoit Lavraud (LAB, France)
Sae Aizawa (LPP, France)
Lea Griton (LESIA, France)
Moa Persson (IRF, Sweden)
Support Scientist
Shoichiro Yokota (Osaka University, Japan)
Andrei Fedorov (IRAP, France)
Support engineers
Alain Barthe (IRAP, France)
Emmanuel Penou (IRAP, France)
Henry-Claude Seran (IRAP, France)

Instrument Specifications

Field of view 8 deg × 360 deg
Angular resolution 22.5 deg × 11.25 deg
Energy range 3 eV–25,500 eV (Mercury mode)
3 eV–3000 eV (solar wind mode)
Energy resolution ΔE/E ∼ 10% (at full G-factor)
Stepping energies and cadence Full energy sweep with 64 contiguous energy channels every 16 or 32 times per 4 s spin
Time resolution to obtain the full 3D velocity distribution function Half a spin period, 2 s (using a single analyzer)
Quarter of a spin period, 1 s (using the two analyzers)
Geometrical factor: MEA1 max./min. 4.0×10−3/6.7×10−5 cm2sreV/eV
Geometrical factor: MEA2 max./min. 2.0×10−3/4.0×10−6 cm2sreV/eV
Mass 2.598 kg (for MEA1 + MEA2) +0.460 kg for their thermal shields
Power 2.260 W (average for MEA1 + MEA2)
3.460 W (peak for MEA1 + MEA2)
1.880 W (stand-by for MEA1 + MEA2)
Dimensions 177 mm×120 mm ϕ (MEA1, MEA2)
Dimensions 0.1 kbits/s (L-mode)
2.5 kbits/s (M-mode)
11 kbits/s (H-mode)
after factor 3 compression for MEA1 + MEA2

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