Modeling study on temporal nonlinear behaviors in CO₂ dielectric barrier discharges under Martian pressure

Abstract

In recent years, dielectric barrier discharges (DBDs) have become one of the most potential candidates for in situ resource utilization of CO2 ${\text{CO}}_{2}$ in the Martian atmosphere. The nonlinear behaviors in DBDs are directly associated with the stability of discharges, and understanding the formation mechanism of the nonlinear behaviors can effectively enhance the ability to control the plasmas. In this paper, to further explore the underpinning physics of temporal nonlinear behaviors in CO2 ${\text{CO}}_{2}$ discharges, the tailored sinusoidal voltages with power‐on and power‐off phases are applied to ignite the plasmas under Martian pressure. The simulation results from a fluid model with hundreds of reactions show that the discharge can evolve from period‐one state into period‐four state via period‐two state by reducing the power‐off duration; the electron density drops rapidly and the heavy ions of CO2+ ${\text{CO}}_{2}^{+}$ and CO3− ${\text{CO}}_{3}^{-}$ become the dominant charged particles after the discharge is extinguished. With the power‐off duration further reduced, the heavy ions produced by the previous discharge cannot be completely dissipated and remain in the sheath region to enhance the electric field before the next discharge event; thus, the next ignition takes place more easily with a reduced breakdown voltage and a lower discharge current, indicating the discharge transits from a period‐one state to a period‐two state. In the transition from period‐two discharge to period‐four discharge, the heavy ions produced by the second discharge event cannot be completely transported to the surface of barriers, affecting the ignition in the third voltage period. When the power‐off duration is less than 10 μs $\mathrm{\mu s}$ in the simulation, electrons become the dominant residual negative charges in the discharge region, and the rapid increase in memory voltage results in a smaller positive discharge current and a stronger negative discharge current. As the power‐off duration continues to decrease, the discharge undergoes an inverse period‐doubling bifurcation from reverse period‐four discharge to reverse period‐two discharge. This study provides a deeper insight into the underlying physics of nonlinear behaviors in CO2 ${\text{CO}}_{2}$ DBDs under Martian pressure.