Analysis and design of capacitor-fast-discharging trigger generator

In order to gain high voltage electric pulse with fast rise time, the circuit of capacitor-discharging trigger generator is analyzed. The influential factors, including the parameters of discharging circuit and gas spark switch, and the forming process of trigger signals on the load with high impedance, are discussed. Moreover, the effects of two different types of ground units are also discussed. Thereby, the principles of designing and choosing the units in the capacitor-discharging trigger generator with low jitter and fast rise time are given. The inductance of units in the discharging circuit, including capacitor, switch and the connections etc, should be minimized. It is revealed that, in order to reduce the jitter of trigger, the gas spark switch with short gap should be selected, and the output pulses number should be limited. If the length of cable is not long enough, the performance of unit to be triggered may be affected as well. Based on the analysis result above, 30 kV and 100 kV trigger generators are designed. The rise time of 30 kV trigger generator is about 12 ns, the amplitude on the load with high impendence is about 44 kV, the rise time of 100 kV trigger generator is about 10ns, and the amplitude is about 170 kV.