New directions in fusion magnet development

As part of the ERDA Division of Magnetic Fusion Energy effort to achieve fusion power by the end of the century, superconducting magnet programs were established at several of the national laboratories with the support of numerous industries. Recently, these program goals have been reviewed and modified to reflect new directions in fusion research. The development of superconducting toroidal field coils has been assigned first priority for the Experimental Power Reactor. This effort, centered at ORNL, will have the extensive support of industry, so that large construction capability can be encouraged. Ohmic heating coils for tokamaks promise to be an even more difficult task, and an expanded effort will be initiated as funds become available. Magnets for mirror confinement systems should have the highest fields practical. Accordingly, LLL has been funded to develop multifilamentary niobium-tin for future might experiments. If successful, the material might complement the recent trend toward higher field tokamaks as well. Energy Storage development at LASL is concentrating on inductive storage for 1 msec discharge and a superconducting homopolar generator for 30 msec to 1 sec discharge times. The stainless steel structure is a major cost element of any magnet system. However, recent calculations have shown that a magnetic coil form affects the toroidal field ripple in the EPR by only a few parts in a thousand. Thus, an opportunity exists to characterize and develop less expensive alloys for low temperature magnet structures.