Low energy particle spectrometer for 3-axis stabilized spacecraft

Abstract

Most of the recent satellite-borne instrumentation for low energy charged particle measurement adopts tophat type electrostatic analyzers. Since the top-hat type electrostatic analyzers have wide field of view of 2π radian with uniform transmission characteristics, they are suitable for low energy charged particle measurement by spin-stabilized spacecraft. However, 3-axis stabilized spacecraft is favored in most of the planetary missions due to the affinity with imaging instruments. Therefore, for the future planetary plasma observations, it is quite important to develop lightweight, low-power consumption and compact low energy charged particle analyzers for 3-axis stabilized spacecraft. In order to realize 3-D field of view on 3-axis stabilized spacecraft under limited resources, ASKY-ESA (All SKY-ElectroStaitc Analyzer) was developed. ASKY-ESA consists of FOV (Field Of View) scanning deflectors at the entrance and spherical/toroidal electrostatic deflectors inside. The FOV is electrically scanned between +/−45 degrees around the center of the FOV, which is 45 degrees inclined from the axis of symmetry. Since ASKY-ESA has hemi-spherical field of view, three-dimensional space is covered by two ASKY-ESAs installed on spacecraft panels opposite to each other. ASKY-ESA is also suitable for low energy charged particle measurement on a surface of airless heavenly bodies, for example, the Moon, Martian satellite Phobos, and numerous small objects/asteroids.

High‐speed MCP anodes for high time resolution low‐energy charged particle spectrometers

“…One of the solutions for a 3‐D phase space density measurement independent of the spacecraft's spin motion is to use two analyzers with hemispherical fields of view installed on a spacecraft back to back. An example of such an analyzer is ASKY‐ESA (All SKY‐ElectroStatic Analyzer), originally developed for 3‐D phase space density measurement on a three‐axis stabilized spacecraft [ Saito , ]. ASKY‐ESA consists of FOV (field of view) scanning deflectors at the entrance and spherical/toroidal electrostatic deflectors inside.…”