Numerical Study of the Influence of Pressure on the Dynamics and Complex Bifurcation Processes of the Low-Pressure DC Glow Discharge

We study the dynamics and complex bifurcation processes of the low-pressure direct current (DC) argon glow discharge system on the basis of a spatially dependent model. In particular, a plasma fluid model based on the drift-diffusion approximation is established, and the Resistor-Capacitance (RC) external circuit is coupled into the model as a boundary condition. The bifurcation processes, which are characterized by the temporal evolution of the discharge voltage and current, are obtained by changing the control parameter, i.e., the discharge pressure p. The results indicate an order-chaos-order transition due to changes in pressure, showing that increasing pressure can induce similar transitions in discharge modes as increasing the applied voltage U-0 . The applied voltage is introduced as second parameter and a finite number of "bubbles" bifurcation structure is formed on some cross-sections of the two-parameter plane. It is suggested that the chaotic oscillations exist only under certain parameter range. Far from the certain parameter region, only periodic behaviors can be observed. The results can provide some guidance for plasma applications in practice.