Global Modeling of Microwave Discharge Plasma in Humid Air Within a Cavity Filter: Reaction Kinetics and Dynamics

With the continuous increase in power capacity of spacecraft radio frequency payloads, low-pressure discharge effects have become a significant factor threatening the safe operation of spacecraft payloads. Clarifying the low-pressure discharge effects and their plasma evolution mechanisms is of great importance for elucidating the underlying discharge processes and proposing effective preventive measures. Based on the characteristics of the actual operating environment of spacecraft microwave payloads, this paper proposes a global simulation model for low-pressure discharge plasma in humid air. The validity of the model was verified through online diagnostic experiments on low-pressure discharge plasma. Using the constructed global plasma model, the influence of key parameters such as pressure and humidity on electron and ion densities in the plasma was investigated, revealing the impact mechanisms of initial discharge conditions on plasma characteristics. The potential hazards of these factors to spacecraft microwave payloads were also discussed. This model provides a foundation for improving the accurate prediction of key parameters in low-pressure discharge.