Measurements of Ionospherically Relevant Ion-Ion and Ion-Neutral Cross Sections

We present experimentally determined ion-ion and ion-neutral collisional cross-sections for various ionospheric compositions at different altitudes, conducted in a laboratory environment. Cross-section measurements were performed in the Space and Beam Experiment (SABER) at West Virginia University using an ion gun to accelerate H2, O2 He, Ar, N, and N2, and NO ions. The ions are directed through a gas mixture and the transmitted current collected with a Faraday cup. To recreate the conditions and gas composition of the ionosphere at various altitudes, an array of mass flow controllers was employed controlling H2, O2 He, Ar, and N2, and NO composition. Additionally, a helicon source is used to produce a level of ionization corresponding to the altitude being simulated. Current models of ionospheric ion-neutral collision frequencies show significant variability compared to estimates derived from radar observations. Accurate measurements of these collision cross-sections are crucial for enhancing our understanding of Magnetosphere-Ionosphere-Thermosphere coupling.