[P-CG20] Future missions and instrumentation for space and planetary science

[PCG20-P06] Pre-flight calibration of the ion energy mass spectrum analyzer for the Martian Moons eXploration (MMX) mission

*Shoichiro Yokota¹, Yoshifumi Saito², Kazushi Asamura², Satoshi Kasahara³, Yuuki Kitamura¹ (1.Graduate School of Science, Osaka University, 2.ISAS/JAXA, 3.Graduate School of Science, The University of Tokyo)

Keywords:Space plasma measurements, Mass analysis, Martian Moons eXploration (MMX) mission

We have developed an ion energy mass spectrum analyzer for the Martian Moons eXploration (MMX) mission to measure the three-dimensional velocity distribution function and mass profile of low-energy ions around the Mars-Moon system. The ion analyzer employs nearly the same measurement techniques as that of Ion energy Mass Analyzer (IMA) for the Kaguya mission and mass spectrum analyzer (MSA) for BepiColombo/MIO. The hemispheric field of view (FOV) is acquired by a couple of angular scanning deflectors, and the energy/charge and mass/charge are determined for each ion by an electrostatic analyzer and a linear-electric-field (LEF) time-of-flight (TOF) analyzer, respectively, with an enhanced mass resolution of M/ΔM∼100.
The ion analyzer, together with magnetometers, constitutes the mass spectrum analyzer (MSA), one of the scientific instruments on board the MMX spacecraft. The performance tests and pre-flight calibration presented here were conducted from the end of 2022 to the beginning of 2024. The FM of MSA was handed over to the MMX spacecraft system. The FM of MSA was integrated into the spacecraft exploration module, and the preflight test of the spacecraft system has started. We will report on the instrumentation of the ion analyzer, and results of the performance tests of its flight model (FM) comparing with that estimated with a numerical model for its design.