Azimuthal Transmission Lines for Inductive Voltage Adders With Four PFLs Driving Simultaneously or Separately

Abstract

In this paper, an inductive cell driven by four pulse forming lines (PFLs), capable of operating at two modes to create a single pulse or four separate pulses, is proposed. A single hardware configuration of azimuthal lines must meet the different requirements of the two operating modes. The optimizations and tradeoffs of azimuthal lines for these two modes are presented. Four candidate azimuthal line configurations that are compatible with either mode are proposed. The cell output voltage and azimuthal uniformity of feed currents are simulated, respectively. The simulation results indicate that the cylinder azimuthal line with four equidistant tabs connected to the cathode palates is the most suitable configuration. As the input pulses are 1000 kV and 25-ns rise time, at the mode with four PFLs driving simultaneously, the cell would produce a pulse with a peak of 865 kV and a rise time of 46 ns into 1.5-load. Meanwhile, it could create four separate pulses of 980 kV and 32-ns rise time into 5-load with each PFL driving separately. In this case, the azimuthally asymmetric coefficient is calculated to be 25.6%. In addition, the voltage of undriven ports, i.e., the voltage applied across the separating switches, is estimated to be about 1150 kV. Index Terms-Azimuthal transmission line, magnetically insulated inductive voltage adders (MIVAs), pulse forming line (PFL),separating switch, symmetrizing current flow.