[P-CG20] 宇宙・惑星探査の将来計画および関連する機器開発の展望

[PCG20-10] Development of ion energy-mass spectrum analyzer for observations of low-energy ions originating from the ionosphere using computer simulation

*寺澤 賢哉¹、永谷 朱佳理¹、浅村 和史²、三好 由純¹ (1.名古屋大学太陽宇宙環境研究所、2.宇宙航空研究開発機構宇宙科学研究本部)

In the inner magnetosphere, there are oxygen ions, nitrogen ions, and molecular ions that originate from the ionosphere and traverse along the Earth’s magnetic field lines. The heating mechanism for accelerating cold ions (~1 eV) in the ionosphere to suprathermal energy range (~10 eV) remains unclear. To clarify this mechanism, we have developed a new suprathermal ion energy-mass spectrometer for the upcoming LAMP-2 sounding rocket experiments and the future satellite mission focused on the polar ionosphere, “FACTORS”. The instrument consists of an electrostatic energy-per-charge analyzer and a mass analyzer utilizing a linear-electric field (LEF) structure based on the time-of-flight (TOF) method. Using computer simulations, we have designed a system incorporating multiple electrodes and have adjusted their voltage to control both field-of-view (FOV) and sensitivity to the electrostatic analyzer. The design study has resulted in the realization of a wide FOV and flexible control of sensitivity are realized. Additionally, we have also optimized the LEF-TOF analyzer. By attaching several electrodes and adjusting their voltage in the analyzer, we have successfully designed to improve the efficiency and confirm the discrimination of ions mass species, especially, between N+ and O+. In this presentation, we report on the current status of the development and outline of our future plans.