| Retarding potential analyzers (RPAs) are a common instrument used to measure velocity, temperature, density, and composition of plasmas in the ionosphere. These instruments utilize a series of biased grids to create potential energy barriers to filter out incoming plasma particles below a certain energy. The grids are meant to approximate ideal potential planes. The structure of the grids, however, introduces nonuniformities in the potential map within the instrument that leads to errors in the measured parameters. Flat, woven, and double-thick flat grids are investigated in both single and double-grid configurations using a numerical technique to determine the influence the grid geometry has on the errors in the measured parameters. These errors and their causes are examined in detail. Three possible mitigation strategies are presented to reduce these errors. |
