Triple‐Dome Electrostatic Energy Analyzer With 360° Field‐Of‐View for Simultaneous Measurements of Ions and Electrons

Abstract The demonstrative space plasma physics communities in the world have been conducting intensive research and development activities for instrument miniaturization because compact and lightweight sensors are required for installation on micro/small satellites and CubeSats in ongoing and future space exploration missions. Recently, we designed a novel type of space plasma instrument capable of simultaneous energy analyses of low‐energy (∼eV to several 10s of keV) electrons and ions with a single sensor head consisting of triple‐dome analyzer with triple‐layer collimator for covering 360° field‐of‐view similar to that of the prevailing top‐hat type. Two separate but correlated electrostatic fields, produced by a single high‐voltage supply unit in double gaps of the triple‐dome/layer structures, are used for electron/ion energy analyses. In the breadboard model (BBM) designed here, the energy/angular resolutions and the analyzer constants (ratios of measured particle energy to applied voltage) are approximately 9.0%/3.5° and 4.0, and 10%/4° and 4.4 for the electron and ion energy analyses, respectively. We also fabricated the first BBM of the triple‐dome type of electrostatic analyzer for experimental performance tests in electron/ion beamline facility. According to the experimental data by the two‐dimensionally position‐sensitive particle detector, the calibrated properties of energy/angular analyses and the other sensor performance show good agreement with numerical design results. The performance of the triple‐dome analyzer would satisfy observation requirements, as represented by measurements of three‐dimensional velocity distributions of electrons and ions in future missions using spin‐type microsatellites/CubeSats under stringent resource conditions.