Cross‐Section Measurements for Argon and Nitrogen Ions in Argon, Nitrogen, and Oxygen Neutrals

Abstract Collisions between ions and neutral atoms or molecules regulate the electrical conductivity in Earth's ionosphere and therefore play an important role in closing the magnetospheric current system. Here, we present measurements of the total collision cross‐sections of and ions in the energy range from 1 to 7 keV, scattered from mixtures of different species of neutrals (, and ). Cross sections for on the individual target species are well known and were used to validate the experimental process that was then used to measure the cross sections in mixtures of the target species. The measurements were conducted in the Space and Beam Experimental Device (SABER), which includes an ion gun to accelerate selected ion species and a movable Faraday cup that enables two different methods to measure the total cross section. The total scattering cross section of a gas mixture is commonly approximated as a weighted sum of the cross sections of the individual species, based on their respective concentrations. However, our findings indicate that the total scattering cross‐section for target gas mixtures is not always equal to the proportional sum of the individual cross‐sections of the mixture components.