Analysis of the Properties of Plasma and Sputtering Rates for Alternative Propellants Used in Gridded Ion Thrusters

Exploring different propellants for electric propulsion systems is crucial. A computational technique employing the particle-in-cell (PIC) method examines the plasma properties associated with Krypton, which is considered a viable propellant option for gridded thrusters. Parameters for plasma simulation, a collision model, and a basic ion optics setup have been established. The analysis focuses on interactions between particles and plasma diagnostics. Moreover, molecular dynamics simulations are performed to evaluate sputtering based on a Krypton-Graphite configuration. The primary objective is to determine the sputtering rate and its potential impact on the lifespan of space propulsion systems. The total energy of particles and the velocity of electrons experience slight fluctuations while maintaining a consistent trend. In contrast, the corresponding values for ions show an upward tendency, potentially reaching a stabilization point. Furthermore, a comparison is conducted between the Yamamura empirical model and the sputtering yield of the target material. The initial model demonstrates a steady increase, while the interaction of Krypton ions with the target leads to a minor decline, followed by a gradual rise, eventually aligning with the final defined energy range of the empirical calculations. These findings provide insights that may lead to the identification of additional viable materials for ion engines, compatible with a range of propellants.