Background
The ElectroStatic Mirror Imager (ESMI) IR seeks to design, fabricate, and validate the performance of a low-dispersion electrostatic mirror, enabling new high-mass-resolution ion and energetic neutral atom measurements. The degree of electron dispersion is a critical factor in the performance of an electrostatic mirror, as the dispersion directly impacts accuracy in timing and determination of the initial particle trajectory. As such, lowering the dispersion of the electrostatic mirror assembly can greatly increase the capabilities of SwRI-built instrumentation and so enable the necessary measurements for addressing current open questions in Heliophysics. Performance validation involves characterizing temporal and angular dispersion through an assembled ESMI using a radioactive source in a relevant environment. Successful completion of this IR will enable higher performance electrostatic mirror-based instruments to be proposed in future NASA Announcements of Opportunities.
Approach
The project conducted a parametric study of various grid characteristics (2D spacing, wire thickness, potential use of a variety of wire thickness/spacing across grid domain) and bias voltages to fully understand the impacts of different grid realizations on the electro-optics of an electrostatic mirror assembly. This parametric evaluation then informed the selection of grids and voltages for prototype fabrication and set requirements on mechanical design tolerances. Upcoming analysis of lab calibration results will further inform understanding of dispersion within an optimized electrostatic mirror, enabling future, externally funded instrument proposals.
Accomplishments
Analysis of the various design trades have been completed, and the full instrument mechanical design has been finalized. The project has initiated parts fabrication and procurements to enable prototype assembly and performance validation to begin later this year.