The reliability assessment of JET operation at a toroidal field of 4.0 T

The toroidal magnetic field coils on JET were designed to operate at 3.4 T. During the JET tritium campaign (DTEI, 1997) /spl sim/150 pulses were run at 3.8 T. Recently operation at 4.0 T has been commissioned and used briefly in plasma operation. An extensive analytical and experimental study over the last four years has concluded that limited operation at 4.0 T in a wide range of scenarios is acceptable.