The THEMIS ESA Plasma Instrument and In-flight Calibration

• Published in: Space science reviews 2008-12, Vol.141 (1-4), p.277-302
• Main Authors: McFadden, J. P., Carlson, C. W., Larson, D., Ludlam, M., Abiad, R., Elliott, B., Turin, P., Marckwordt, M., Angelopoulos, V.
• Format: Article
• Language: English
• Subjects: Aerospace Technology and Astronautics; Astrophysics; Astrophysics and Astroparticles; Auroras; Magnetic fields; Physics; Physics and Astronomy; Planetology; Plasma; Scientific apparatus & instruments; Space Exploration and Astronautics; Space Sciences (including Extraterrestrial Physics; Spacecraft
• ISSN: 0038-6308; 1572-9672
• DOI: 10.1007/s11214-008-9440-2

The THEMIS plasma instrument is designed to measure the ion and electron distribution functions over the energy range from a few eV up to 30 keV for electrons and 25 keV for ions. The instrument consists of a pair of “top hat” electrostatic analyzers with common 180°×6° fields-of-view that sweep out 4 π steradians each 3 s spin period. Particles are detected by microchannel plate detectors and binned into six distributions whose energy, angle, and time resolution depend upon instrument mode. On-board moments are calculated, and processing includes corrections for spacecraft potential. This paper focuses on the ground and in-flight calibrations of the 10 sensors on five spacecraft. Cross-calibrations were facilitated by having all the plasma measurements available with the same resolution and format, along with spacecraft potential and magnetic field measurements in the same data set. Lessons learned from this effort should be useful for future multi-satellite missions.