Problems for the next stage applications of superconducting magnets

The superconductive industry is golng to make a big step and many problems for practical use have come up. Points of issue for the next stage of superconducting magnet applications are shown and discussed. A review of the present state of applications such as nuclear fusion, MRI, machine are shown at first. Limitations by critical current, stress and energy dumping for magnet design are shown in a map of average current of magnet(J) vs its energy(E), and points of problems are discussed referring to the location in the map. Rough features of magnets can be realized by this map. As topics for the next stage high field superconductive materials, AC cable, SMES, and problem of cost are mentioned, in which possibilities of practical use of high Jc materials in high field, power frequency application such as transformer, and a huge magnet application are discussed together with examples of cost estimation.