The Influence of Electrode Surface Mercury Film Deformation on the Breakdown Voltage of a Sub-Nanosecond Pulse Discharge Tube

A sub-nanosecond pulse discharge tube is a gas discharge tube which can generate a rapid high-voltage pulse of kilo-volts in amplitude and sub-nanoseconds in width. In this paper, the sub-nanosecond pulse discharge tube and its working principles are described. On that basis, a view is presented that the breakdown voltage of the sub-nanosecond pulse discharge tube is dynamic. Because of the phenomenon that the deformation process of the mercury film on the electrode surface lags behind the charging process, the mercury film deformation process affects the dynamic breakdown voltage of the tube directly. The deformation of the mercury film is observed microscopically, and the dynamic breakdown voltage of the tube is measured using an oscillograph. The results show that all the parameters in the charging process, such as charging resistance, charging capacitance and DC power supply, affect the dynamic breakdown voltage of the tube. Based on these studies, the output pulse amplitude can be controlled continuously and individually by adjusting the power supply voltage. When the DC power supply is adjusted from 7 to 10 kV, the dynamic breakdown voltage ranges from 6.5 to 10 kV. According to our research, a kind of sub-nanosecond pulse generator is made, with a pulse width ranging from 0.5 to 2.5 ns, a rise time from 0.32 to 0.58 ns, and a pulse amplitude that is adjustable from 1.5 to 5 kV.