Experiment investigation on nanosecond pulse discharge under static air and big volume condition has been performed under different air pressure, discharge distance and voltage. Research shows that under the condition of the length of 200mm and the pressure of 250Pa, as voltage increases the discharge region extend from near of the conical electrode to the whole channel. When the voltage is 12kV, discharge can fill the whole channel; and with the pressure rise the initial discharge voltage increases. It is found that nanosecond pulsed ionization instability appears when the voltage is increased to a certain extent, as the radial fluctuations in the plasma when the pressure is relatively low, and the discharge tends to break initially uniform nonequilibrium plasma into narrow hot arcs at relatively high pressure. Analysis indicates that shorter rise time, shorter pulse width and higher voltage for the source are needed to realize long distance, large volume homogeneous plasma.%采用纳秒脉冲电源,在静止空气条件下,开展了不同气压、放电距离和电压条件下的大体积纳秒脉冲放电实验研究.研究表明,当长度固定为200mm时,气压为250Pa时,随着电压的增大,放电区域从圆锥电极附近扩展到整个通道.当电压为12kV时,放电布满整个通道；随气压升高,初始放电电压增大.实验中发现在电压升高到一定程度时纳秒脉冲电离出现不稳定性,表现在气压相对较低时等离子体出现径向波动,气压相对较高时非平衡等离子体放电向电弧放电转变.分析认为,为了实现大体积均匀放电等离子体的产生,阻止放电不稳定性发生,应该采用上升沿时间更短,脉宽更小,电压更高的纳秒脉冲电源.
展开▼
