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The regulation of memory effect that the residual charges generated during and after discharge act on the initiation and development of subsequent discharge is explored by adjusting the pulse parameters, which have an influence on the discharge characteristics. The memory effect is quantified by the measurement of 'wall voltage' through a series of reference capacitors. The influences of memory effect on the discharge properties corresponding to rising/falling time 50-500 ns, pulse width 0.5-1.5 μs, and frequency 200-600 Hz are analyzed. It is found that the 'wall voltage' increases from 1.4 kV to 2.4 kV with rising/falling time from 50 ns to 500 ns, it varies in the range of 0.18 kV with frequency of 200-600 Hz, and 0.17 kV with pulse width of 0.5-1.5 μs. The propagation velocity of wavelike ionization under the negative pulse slows down from 2184 km s −1 to 1026 km s −1 as the rising/falling time increases from 50 ns to 500 ns due to the weakening of the electric field by the surface memory effect. More intense and uniform emission can be achieved through faster rising/falling time and higher frequency based on the volume memory effect, while pulse width has less influence on the emission uniformity. Furthermore, similar laws are obtained for spectral and discharge intensity. Therefore, the memory effect is most effectively regulated by rising/falling time, and the discharge properties are affected by the surface and volume memory effect.

An exploration of discharge efficiency and uniformity improvement by using pre-ionized bipolar pulse method in dielectric barrier discharge (DBD) device under atmospheric pressure is conducted. Through utilizing the pre-ionized charged particles on the dielectric surface, the amplitude of the applied pulses for sustaining discharge can be significantly decreased. By analyzing the influence of “built-in” electric field from surface charges on discharge efficiency and uniformity, a scheme of pre-ionized bipolar pulse method is proposed. Since the property of “built-in” field is closely dependent with pre-ionized pulse parameters, such as amplitude, pulse number, and polarity, the discharge uniformity and efficiency under different combinations of pre-ionized pulse parameters are investigated. According to experimental results, the discharge efficiency of the proposed method is increased by 11.8% and 17.4%, and the production efficiency of active species of N2(C3Πu→ B3Πg) is increased by 10.4% and 89.5% compared with a conventional bipolar pulse and positive pulse method, respectively, in ambient air. Moreover, the uniformity of DBD discharge is improved, and the maximum intensity difference between discharge regions is decreased from ∼20% to ∼5% compared with the one driven by the conventional positive pulse.