Explosively produced megagauss fields and applications

We describe various explosive magnetic flux compression devices that produce pulsed megagauss fields, and a number of applications in which they have been used. Among the systems described are relatively simple ones that generate fields up to 250 T in large fixed volumes, and cylindrical implosion systems that produce fields in excess of 1000 T. Small fixed volume systems are described that may be used in the laboratory. They require only small amounts of explosive and can produce 100 T fields in coils 25 mm long and 10 mm diameter. We discuss measurements made on various materials in megagauss fields, often at cryogenic temperatures, including magnetoresistance, magnetic susceptibility, optical absorption, Faraday rotation, and Zeeman splittings. We also discuss experiments in which large magnetic pressures have been used to compress solid deuterium isentropically. In flux compression devices part of the energy of the explosives is converted to electromagnetic energy. This has led to their use as compact single-shot high power energy sources. At times, it is necessary to transformer couple loads to the device outputs. We describe successful operation of transformers in 165 T fields, and suggest that they can operate in much higher fields.