A low-impedance, high-voltage direct drive transformer system

The basic design for a 1000 kV, repetition-rated direct-drive transformer system is presented, and solutions to the problems of high magnetic coupling and minimum droop characteristics are proposed. It is shown that air and partial-core transformers can be adapted to multimicrosecond, direct-drive applications where output voltages up to at least 1 MV are required. To achieve adequate coupling, these transformers must operate within winding stresses between 0.5 and 1 MV/cm. Experiments have shown that film-insulated spiral windings can withstand these stress levels when they are impregnated with a high-dielectric-constant liquid such as ethylene glycol