High-repetition-rate Nanosecond Spark Gap Switch

In order to improve working frequency of the gas spark gap switch,a unipolar pulse with the rise time and pulse duration in the order of microsecond is used as the primary source,a repetitive pulse with the frequency of several kilohertz is generated,which has the rise time and the pulse duration in tens of nanoseconds with the nanosecond gas spark gap switch.The frequency and amplitude of the output pulse can be continuously adjusted by the primary pulse source and the parameters(gap distance,gas pressure,gas composition,etc)of the gas spark gap switch,and the pulse width is determined by the value of the load resistance.By changing the running conditions such as gas pressure in the switch chamber,different gas compositions and ratios,different amplitudes of the bias DC voltage and so on,the amplitude and duration of the first two continuous output pulses are measured respectively in different interpulse durations(200～1 000 μs)of the primary pulse.Consequently,the effect of working conditions on the voltage recovery characteristic is researched under different pulse frequency.As a result,the characteristic of voltage recovery of the gas spark gap switch could be improved by these methods:increasing the gas pressure of the switch,mixing proper quantities SF6 into air(20% in the pressure),applying appropriate bias DC voltage(positive DC voltage with the amplitude of 1 kV)and so on.