Study on Characteristics of Low-Temperature Subatmospheric Air Surface Dielectric Barrier Discharge Under Square Wave Voltage

Based on the simulation system, this article constructs a low-temperature and subatmospheric pressure air surface dielectric barrier discharge (SDBD) model with 37 plasma chemical reactions composed of 18 particles. Through the model, the discharge characteristics of a positive square wave voltage with amplitude of 1200 V, frequency of 3.3 and 4 MHz, duty cycle of 30% and 50%, and rise (fall) time of 35 and 70 ns are studied. Under the same reduced electric field, when the frequency and duty cycle increase, the electron density increases, but the electron temperature and space charge density are almost constant; when the rise (fall) time increases, the electron density decreases, the electron temperature also decreases from 16 to 14 eV, and the peak space charge density shows a slight downward trend. With the increase of altitude, the electron density decreases, the electron temperature increases, and the space charge density is almost unchanged.
$\text{O}_{2}^{+}$
plays a leading role in the discharge process, affecting the changes of other particles, and the spatial distribution of cluster ion
$\text{O}_{4}^{+}$
is diffusive. Second, the increase of relative dielectric constant leads to the decrease of the electric field at the streamer head, which leads to the decrease of propagation velocity. Finally, due to the symmetry and repeatability, the SDBD under square wave voltage presents the characteristics that the absolute values of positive and negative discharge current density peaks are the same and the peak values gradually increase.