This paper describes the theory and design of Rogowski-wound coils used to measure nanosecond electrical curent pulses in the megampere range. The coils have risetimes of less than one nanosecond, microsecond decay times and typical sensitivities in the range of 10−3 to 10−4 V A−1. They operate in large radiation fields, under intense electron bombardment and at high rates of current rise.

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This theoretical investigation addresses the propagation of a power pulse in a long magnetically insulated vacuum transmission line (MITL). Relativistic Brillouin flow, with an arbitrary choice of the potential Vm at the flow boundary, explains the relationships among anode voltage, anode current, and cathode current that have been observed experimentally. The results of this investigation suggest that minimum energy considerations may be used to establish the value of Vm and hence determine the operating point of the MITL. This operating point compares very favorably with experimental data and with results from numerical simulations.

The propagation of a 1.8-MV 80-kA power pulse in a 10-m-long 41.6-Ω impedance coaxial vacuum transmission line has been investigated experimentally. The onset of magnetic insulation has been correlated to attainment of the critical current. Measurements of boundary (cathode) current suggest that 50–60% of the current flows in space charge in the axial direction between the conductors. The pulse sharpens as it propagates and attains a stationary shape. Pulse rise times of 4 ns were observed. Propagation velocities equal to 0.7c have been measured. Power and energy transports as high as 90 and 70% have been observed. The peak power density in the transmission line was 2×109 W cm−2.

This paper describes the development of a resistive voltage divider to measure pulsed voltages in excess of 2 MV in vacuo for approximately 100 ns. The monitor can measure either positive or negative polarity by changing the low voltage insulator and reversing the remainder of the insulators and gradient rings.