Subnanosecond rise time of high voltage pulses in ferrite loaded coaxial line

In this paper, Ni-Zn ferrite loaded coaxial line, using oil as insulation, with subnanosecond rise time at the input pulse voltage up to 360 kV into a 50 load is described. The dependence of the shock front development on the line length and pulse voltage was investigated. The experimental data were compared with analytical predictions of early theory. The experimental and expected results are shown to be in quite good agreement. A modified ferrite-loaded line with lower impedance was fabricated in order to increase its magnetic field. The ferrite loaded line showed stable work at pulse repetition frequency of 100 Hz and the shortest rise time of 0.7 ns has been achieved. Benson et al have proposed to use an axial magnetic field bias for further pulse sharpening. Magnetic bias conditions for the optimal pulse sharpening were tested.