Megagauss magnetic fields

Methods of generating magnetic fields in excess of one megagauss are described and discussed. Particular attention is given to explosively driven flux-compression experiments, which at present can generate the highest fields. The discussion of the experimental techniques is divided into three parts: high explosives, initial field and the compression process. Flux-compression theory deals with the dynamics of the metallic `liner' which compresses the flux, and with the magnetic field diffusion into the liner, which results in heating the liner material above the boiling point. Theoretical limits on the highest attainable fields are discussed. Explosively driven current generators which can produce energy pulses of several megajoules are also described. Finally, experiments to generate megagauss fields by means of capacitor-bank discharges are reviewed, and an outlook is given on applications of megagauss fields in various domains of experimental physics.