# Investigation of the Opposite-Electrode Effect on the Planar Solid-State Pulse-Forming Line
## 5 Experimental Results  
Based on the geometric parameters shown in Figure 1 and the two structures shown in Figure 5, the full-electrode PFL and opposite-electrode PFL were fabricated using glass-ceramic material with a relative dielectric constant of 320. To compare the withstand voltage of the opposite-electrode PFL and the full-electrode PFL, a withstand voltage test was performed. Furthermore, the schematic diagram and circuit diagram of the experimental setup are illustrated in Figure 7. In addition, the test replicated the operational conditions of the PFL under normal circumstances. The load impedance was adjusted to match that of the PFL, while the repetition frequency was set at 10 Hz, and a self-breakdown gas switch was employed. The characteristic impedance of the full-electrode PFL is 1.65 \(\Omega\); in comparison, the characteristic impedance of the opposite-electrode PFL is 1.8 \(\Omega\); therefore, there is a slight difference in the impedance of the load resistors used in the two experiments. The self-breakdown gas switch employed in this experiment features a narrow electrode spacing of approximately 4 mm. The breakdown voltage was established by introducing around two atmospheres of nitrogen, which serves to minimize the inductance of the self-breakdown gas switch. Figure 6: Electrostatic simulation of the two types of PFL: (**a**) distribution of the electric field monitoring lines and (**b**) edge electric strength of the high-voltage electrode. As shown in Figure 8, the following are images of some of the experimental equipment used in this experiment. During the experiment, the DC constant voltage source was connected to the protective resistor and charged the PFL. Among them, the DC constant voltage source can output a voltage of up to 100 kV, with a peak power of up to 2 kW. In order to ensure the safety of the DC source, we selected a protective resistor with a characteristic impedance of 300 \(\Omega\). When the charging voltage of the PFL reached the breakdown voltage of the gas switch, the gas switch conducted through self-breakdown, releasing the energy stored in the PFL to the load resistor through terminal 2. A high-voltage probe was placed at the charge end of the PFL and connected to an oscilloscope. During the experiment, we employed a high-voltage probe with a magnification factor of 10,000 to ensure that the charging voltage remained within the operational range of the oscilloscope. The experimental results show that the withstand voltage of the opposite-electrode PFL is significantly higher than that of the full-electrode PFL. The charging voltage at which the PFL fails, as shown in Figure 9, indicates that the withstand voltage of the full-electrode PFL is approximately 23 kV; in comparison, the withstand voltage of the opposite-electrode PFL is approximately 33 kV. Therefore, under the same conditions, the opposite-electrode PFL has a lower field enhancement at its high-voltage electrode edge, resulting in a higher withstand voltage than the full-electrode PFL. These findings also verify the correctness of the theoretical model and simulation analysis referenced in Sections 3 and 4. It can be concluded from the theoretical analysis and simulation results that the thermal distribution of the full-electrode PFL and opposite-electrode PFL under repetitive frequency operation should be different. To verify this phenomenon, an experiment was conducted with a charging voltage of 18 kV and a repetitive frequency of 20 Hz at a room temperature of approximately 28 \({}^{\circ}\)C. The working conditions of the full-electrode PFL and opposite-electrode PFL were simulated separately and continuously operated for 10,000 and 20,000 runs. Lastly, the surface temperature distribution and temperature frequency distribution of the PFL are shown in Figure 10 (a) and (b), respectively. Figure 7: Withstand voltage test of the two types of PFL: (**a**) the front and top views of the experimental equipment and (**b**) circuit diagram of the experimental equipment.