The development of the JET electromagnetic system

A series of enhancements of the JET apparatus is in the process of being implemented to increase the fusion parameter nsub(iD)Tsub(i)τsub(E) to values required for meaningful D-T operation. Modifications to the electromagnetic system (magnets, power supplies and plasma control) are major features of the new JET development plans, for operation with magnetic limiter up to 4MA and with material limiter up to 7MA. If the electromagnetic, thermal and mechanical assessment of the machine and power supplies, now underway, shows that the indicated extensions of the JET engineering operating space are possible, flat top currents of duration 10s and magnitude 4 and 7MA will be achieved in magnetic and material limiter configurations, respectively. (author)