Power losses and magnetic forces analysis in large dipole magnets cryostat

In the frame of a five year national program on superconducting magnet technology, the design and the manufacturing of a 5 T superconducting dipole magnet with an active length of 2 m for MHD applications is carried on. The magnetic analyses performed in the design process of the cryostat of a superconducting dipole magnet, with on axis magnetic flux density of 5 T and overall length about 4 m are presented. The high values of magnetic flux and stored energy require an accurate evaluation of the eddy currents induced on the cryostat structure during a discharge of the magnet. This evaluation is needed both to design the mechanical structure of the cryostat and to estimate the heating of conducting parts. A comparative study of the structure, using different materials and evaluating the effects of electrical disconnections in the metallic parts, has been performed by means of a three dimensional finite element code. The efficiency of the different solution is compared and discussed