Transformer-based, repetitive pulsed power driver for a dense plasma focus

Abstract

We have previously reported [1] on the design of a Thyratron switched, transformer architecture to drive a more efficient Dense Plasma Focus discharge. This paper describes a compact and portable, 100 kA driver that was assembled and tested with Mather type plasma focus electrodes. The pulsed power system described here is composed of two parallel modules, each of which is based on a hydrogen thyratron switched, 6∶1 step-down transformer. The source is designed to operate at a primary voltage of 10–30 kV with a stored bank energy of 15 J to 136 J and a pulse repetition rate of up to 50 Hz. The overall volume occupied by the source is < 1 m3. The plasma focus anode is water cooled to limit the temperature rise at the anode tip during repetitive operation. The initial operation and testing of the repetitive driver into short circuit and dynamic plasma loads are described. The pulse power system and the electrode thermal management system are discussed and compared with models. The overall system lifetime is also discussed.