MULTIMAG - A MULTIpurpose MAGnetic field system for EPM

This paper describes the home-made MULTIpurpose MAGnetic field system MULTIMAG, a facility composed of compact coil systems carrying high currents. Prominent features of MULTIMAG are (i) The large bore of 400 mm in height and 365 mm in diameter, which supports, in conjunction with the high current densities, the attainability of similarity criteria in the industrial range. (ii) Because the use of ferromagnetic material was strictly avoided in the construction, the rotating, travelling, pulsating, and DC in either homogeneous or cusp configuration magnetic fields may be superimposed linearly. (iii) In order to have as flexible as possible spatio-temporal distributions of the magnetic fields, the power supplies are realised as amplifiers. Each of the seven phases, three for the rotating and the travelling field, respectively, and one for the pulsating field, comprises a pulse width modulated power amplifier controlled by its own freely programmable frequency synthesizer.