The advantages of implementing high magnetic flux density up to 10 T for a commercial size closed cycle disk MHD generator with supersonic flow are discussed, and the technical feasibility of its superconducting magnet is studied, The present study suggests a high performance of the generator with high magnetic flux density. A possible construction of the magnet, in which a special structure is arranged to sustain a large electromagnetic force induced between the coils, is shown. (C) 2001 Elsevier Science Ltd. All rights reserved.