## 3 Results
### Differential and Common Mode Current Components in the Charging Path  
The charging current passes through the current-compensated chokes in differential mode. Figures 18 and 19 show the distribution of the charging current along the charging path according to the position in the generator for an on-time of the solid-state switches of 22 u and 200 u, respectively. Thereby, the currents in the four charging coils situated in the left half of the generator (I\({}_{\text{L,D}}\)) are shown in light blue colour, and the currents in the three charging coils of the right half of the generator (I\({}_{\text{L,D}}\)) are in violet colour. Figure 18: Distribution of the charging current along the charging path according to the position in the generator for an on-time of the solid-state switches of 22 u. The charging currents I\({}_{\text{L,D}}\) through the coils of the left four current-compensated chokes are shown in light-blue colour, and the charging currents I\({}_{\text{L,D}}\) through the coils of the right three current-compensated chokes in violet colour. Thereby, the current decays stepwise from the centre towards both ends of the generator. V\({}_{\text{ch}}\) and I\({}_{\text{ch}}\) denote the charging voltage and the charging current at the generator’s input terminal, respectively. Figures 20 and 21 show a simulation of the current distribution in the charging path for the common mode in the case of an on-time of the switch of 22 \(\upmu\)s. The common mode component of the current is caused by the pulse voltage, which is applied to the current-compensated chokes during pulse generation. Its amplitude is not higher than a few amperes, which is 3.5 A in this simulation. Initially, as long as the rising charging current is still lower than the common-mode current, a part of the magnetic energy in the core of the leftmost current-compensated choke is partly transferred to the stage capacitor C1 and the damping resistor R\({}_{\rm D}\). Hence, as shown in Figure 20, a voltage drop across R\({}_{\rm D}\) appears as long as the common-mode current component of the choke (L1, L2), \(I_{\rm L1I2,C}\), decays. Therefore, during the charging process, the common-mode current component and, hence, the magnetic energy stored in the core of the leftmost current-compensated choke is significantly smaller than is the case for the other current-compensated chokes. This is also visible in Figure 12. Figure 22 shows the voltages across the stage capacitors of the two leftmost stages, C1 and C4, together with their charging currents, which are the currents through D3 and D7, respectively, and the charging current I\({}_{\rm ch}\) of the whole generator just after one pulse. Within approximately the first 120 \(\upmu\)s after the pulse, the voltage V\({}_{\rm C1}\) is higher than the voltages across the remaining stage capacitors, V\({}_{\rm C4,...,C22}\), as initially the charging current of C1, I\({}_{\rm D3}\), is significantly higher than the charging currents of the other stage capacitors. Figure 19: Distribution of the charging current along the charging path according to the position in the generator for an on-time of the solid-state switches of 200 \(\upmu\)s. The notation is equal to Figure 18.  
Subsequently, as long as the charging current for the generator is higher than the common mode component of the current through the current-compensated chokes, the common-mode current component circulates through the leftmost and rightmost generator stages, the bypass-diodes of the stages, and the ground-side coils of the current-compensated chokes. In the equivalent circuit shown in Figure 23, the currents are marked in the corresponding colour. Figure 20 shows the common mode component of the current in the leftmost current-compensated choke comprising L1 and L2, \(I_{\text{L1L2,C}}\), in light-blue colour and the one in the remaining current-compensated chokes \(I_{\text{L,C}}\) in violet colour.