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Low-energy charged particle measurement by MAP-PACE onboard SELENE

  • Yoshifumi Saito116Email author,
  • Shoichiro Yokota116,
  • Kazushi Asamura116,
  • Takaaki Tanaka116,
  • Ryota Akiba216,
  • Masaki Fujimoto116,
  • Hiroshi Hasegawa116,
  • Hajime Hayakawa116,
  • Masafumi Hirahara316,
  • Masahiro Hoshino316,
  • Shinobu Machida416,
  • Toshifumi Mukai116,
  • Tsugunobu Nagai516,
  • Tsutomu Nagatsuma616,
  • Masato Nakamura116,
  • Koh-ichiro Oyama116,
  • Eiichi Sagawa716,
  • Susumu Sasaki116,
  • Kanako Seki816 and
  • Toshio Terasawa516
Earth, Planets and Space200860:BF03352802

Received: 20 March 2007

Accepted: 8 November 2007

Published: 9 April 2008


MAP-PACE (MAgnetic field and Plasma experiment-Plasma energy Angle and Composition Experiment) is one of the scientific instruments onboard the SELENE (SELenological and ENgineering Explorer) satellite. PACE consists of four sensors: ESA (Electron Spectrum Analyzer)-S1, ESA-S2, IMA (Ion Mass Analyzer), and IEA (Ion Energy Analyzer). ESA-S1 and S2 measure the distribution function of low-energy electrons below 15 keV, while IMA and IEA measure the distribution function of low energy ions below 28 keV/q. Each sensor has a hemispherical field of view. Since SELENE is a three-axis stabilized spacecraft, a pair of electron sensors (ESA-S1 and S2) and a pair of ion sensors (IMA and IEA) are necessary for obtaining a three-dimensional distribution function of electrons and ions. The scientific objectives of PACE are (1) to measure the ions sputtered from the lunar surface and the lunar atmosphere, (2) to measure the magnetic anomaly on the lunar surface using two ESAs and a magnetometer onboard SELENE simultaneously as an electron reflectometer, (3) to resolve the Moon-solar wind interaction, (4) to resolve the Moon-Earth’s magnetosphere interaction, and (5) to observe the Earth’s magnetotail.

Key words

Moonplasmamagnetic anomalyalkali atmospheremagnetospheresolar wind