## 3 Results  
### Operation without Damping Resistor R\({}_{\rm D}\)  
A straightforward way of operating the Marx generator is to omit the damping resistor R\({}_{\rm D}\). In order to investigate this mode of operation, the resistor R\({}_{\rm D}\), which corresponds to the resistor R3 in the simulation model according to Figure 3, has been modelled as an open circuit. Figure 4 shows the voltages at the positive charging path of the current-compensated chokes versus the ground potential and the voltage of the ground-side connection of the power supply. Just after charging has ended, magnetic energy, which has been stored in the current-compensated chokes due to the previous pulse generation, causes a voltage pulse. The voltage rises from stage to stage, starting with the rightmost stage and reaches almost the level of the charging voltage at the leftmost stage. As a consequence, the voltage at the ground-side terminal of the power supply (V\({}_{\rm I9,G}\)) in the centre of the Marx generator is shifted to a considerable voltage of approximately 400 V. This voltage amplitude needs to be taken into account when designing the insulation of the power supply versus ground. In the diagram in Figure 4, the voltage V\({}_{\rm I9,G}\) is highlighted in violet colour. Figure 5 displays the voltages across the stage capacitors C1, C4, C7, C10, C13, C16, C19, and C22 according to Figure 3, together with the generator's charging current I\({}_{\rm ch}\). The  
Figure 4: Simulated voltages at nodes in the positive charging path of the current-compensated chokes versus ground (V\({}_{\rm L1,G}\), V\({}_{\rm L3,G}\)\(\ldots\) V\({}_{\rm L13,G}\)), and the voltage of the ground-side connection of the power supply (V\({}_{\rm L10,G}\)). Thereby, the nodes are named according to the respective coil of the current-compensated choke on the right-hand side seen from the node. V\({}_{\rm Ch}\) marks the simulated charging voltage at the input terminal for charging the Marx generator according to the schematic in Figure 3. (R\({}_{\rm D}\): open circuit). charging process of the capacitor of the leftmost stage (C1) continues after the charging process of the other stage capacitors has already ended. Figure 6 shows the voltages across the series configuration of the stage capacitor and the diode connecting the charging path to its positive terminal, together with the voltages across the diodes in the return path for the charging current. When the charging current through the charging inductance \(\mathrm{L_{Res}}\), \(\mathrm{L_{Ch}}\), ceases, the voltage across the series configuration of D3 and C1 (\(\mathrm{V_{D3,C1}}\)) still rises. Hence, the charging of the stage capacitor of the leftmost stage still continues. In Figure 6, \(\mathrm{V_{D3,C1}}\) is shown in red colour. The energy stored in the current-compensated chokes is transferred to the stage capacitor C1 of the leftmost stage. Thereby, the current path comprises the stages' bypass diodes D1, D5, D9... D25, and the diode D32. The voltage across D32 (\(\mathrm{V_{D32}}\)) is almost zero, as it is conducting within the considered time frame. In Figure 6, it is highlighted in violet colour. The voltages across the remaining diodes in the return path for the charging current are positive, so the diodes block due to the voltages induced in the ground-side coils of the current-compensated chokes. On its way back, the current passes the current compensated chokes. Figure 5: Simulated voltages across the stage capacitors C1, C4, C7, C10, C13, C16, C19, and C22 according to Figure 3, together with the generator’s charging current \(\mathrm{L_{ch}}\) (\(\mathrm{R_{D}}\): open circuit).