GEC Student Excellence Award Finalist Presentation - Experimental and numerical investigation of low-pressure iodine plasmas

This work investigates iodine as an alternative propellant for space plasma propulsion. Measurements are taken in a low-pressure inductively-coupled plasma chamber used as the ionization stage of an ion-gridded plasma thruster. Spatially resolved optical and electrostatic diagnostics are developed and implemented. First, charged species are characterized using Langmuir probes and laser-induced photodetachement diagnostics. Then, atomic absolute temperature and density measurements (with a focus on the two first electronic states: the ground state and the first excited state only 0.94 eV above) are conducted using laser absorption spectroscopy at several wavelengths and the TALIF (Two-photon Absorption Laser Induced Fluorescence) technique. Furthermore, the molecular dissociation rate is measured using laser absorption spectroscopy beyond 20000 cm^-1 where the diffusive part of the absorption spectrum leads exclusively to molecular photodissociation. Finally, the experimental results are gathered and compared to a global model and 1D fluid simulations to validate the existing iodine set of cross-sections.