常压单极性纳秒脉冲DBD模式的实验研究

Experimental Study on Mode of Dielectric Barrier Discharge Driven by Repetitive Nanosecond Pulses at Atmospheric Pressure

介质阻挡放电(DBD)是产生低温等离子体的重要方法。实验研究的DBD由上升沿15 ns,半高宽约30ns最高重复频率1 kHz的正极性纳秒脉冲产生,测量了DBD电压、电流以及放电图像。结果表明,空气间隙上发生两次放电,分别发生在施加电压的上升沿和下降沿末端,电流峰值可达百安培量级,峰值功率可以达到MW级。放电图像显示放电分为均匀放电和丝状放电两种模式,且阻挡方式和重复频率都是影响这两种放电模式相互转化的重要因素。

Dielectric barrier discharge（DBD） is an important source for generating transient non-thermal plasma. In this experiment, DBD is produced by repetitive unipolar nanosecond pulses with a rise-time of about 15 ns and a full-width at half-maximum of about 30 ns, and DBD＇s voltage, current, and images are measured. The results show that under unipolar HV pulse, DBD current can reach hundreds of amperes and exhibits bipolar feature. According to the calculation, two discharges take place-the primary discharge is generated at the end of rising curve of the nanosecond pulse, and the secondary one is induced at the end of falling curve of the pulse. Real- time power curve of the DBD also has two peaks, and the amplitude can reach to MW magnitude. In addition, the discharge images show two discharge modes-homogeneous discharge and filamentary discharge, and both barrier pattern and repetition rate can affect the transition of the two modes.