(b) Utcp1=1kV
Fig 2 The influence of different Utcp2(0.3kV、0.5kV、1kV) on PRF: (a) Utcp1=0.3kV; (b)Utcp1=1kV
For this reason, simulation verification is carried out for the case of higher main trigger voltage Utcp1. Figure 3 shows when the Utcp1 is 1kV, the influence of different pre-trigger voltages Utcp2 (0.3kV, 0.5kV, 1kV) on the trigger current. Appropriately increasing the Utcp2 (from 0.3kV to 0.5kV) can improve the current growth rate. However, continuing to increase the Utcp2 to 1kV corresponds to the current rise speed can be seen to decrease. This is because when the Utcp2 = 0.5kV, the current is close to saturation, and further increase of the Utcp2 at this time will cause some electrons to be directly pumped to the anode, resulting in the weakening of impact ionization and the weakening of current.