Simulation study on measurement characteristics of ion energy analyzer

Abstract

The ion energy analyzer (IEA), also known as the retarding potential analyzer (RPA), is widely used as an important tool for measuring plasma energy in situ and is widely used in ionospheric detection satellites. The ion energy of the ionosphere is too low to be stabilized, thus the measurement characteristics of the IEA can’t be effectively studied through experiments. As there is no such problem in simulation, simulation has become a powerful tool for studying IEA. This paper analyzes the low-energy ion measurement characteristics of the IEA through the simulation software COMSOL, introduces the working principle of the IEA, and gives a comprehensive formula derivation for the ion measurement process. Based on simulation and analysis of three candidate design schemes, one of the schemes whose transmission curve is closest to the ideal step function is chosen. In theory, the measurement results of this scheme have the least error. The comprehensive error analysis results at various ion temperatures also show that the gap between the measurement results and the theoretical value of the scheme is narrow. The ion energy distribution can be measured more accurately. Finally, the effects of electric field distortion, plasma sheath, grid alignment and ion temperature are studied. According to these simulations, some experimental phenomena can be reasonably explained.