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

[PCG20-P11] Development of Electron Measurement Technology for Investigating Charging Phenomena on Celestial bodies

*Toshinori Tanaka¹, Takefumi Mitani², Satoshi Kasahara¹ (1.The University of Tokyo, 2.Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency)

Electrical charging of the surface of celestial bodies induces unique phenomena such as dust transport, resulting in mass loss and surface modification, which is important for the evolution of these bodies. Additionally, electrostatic discharges pose a significant risk to spacecraft, making this issue practically important. Previous studies have revealed the global-scale electrostatic potential distribution on the Moon. However, investigations into micro-scale surface potentials, influenced by lunar magnetic anomalies and irregular topography, remain insufficiently explored. To address this issue, multi-point direct measurements of the electron spectrum responsible for lunar surface charging are essential.

In this study, we focused on miniaturizing electron measurement devices to enhance their portability and enable multi-point observations. Specifically, we developed an electron detection technique using a 1 mm-thick solid-state detector (SSD), which is thicker than conventional detectors, to facilitate device miniaturization. We conducted X-ray irradiation experiments using this detector and confirmed an energy resolution of 3.6 keV, demonstrating its viability as an electron detector. Furthermore, theoretical estimation suggests that stacking two SSDs enables electron measurements up to 878 keV. By experimentally validating these findings, we expect that the miniaturization of electron measurement devices utilizing 1 mm-thick SSDs will become feasible.