Design of stabilizing plate of JT-60SA

The stabilizing plate (SP) of JT-60SA has been designed based on an electromagnetic and a structural analysis. The SP plays a role of both a passive stabilizer of magnetohydrodynamics (MHD) instability and a first wall at low field side in combination with a graphite tile. The SP has a double skin structure with 10 mm thickness each in order to have simultaneously high resistivity in the toroidal direction and high strength against plasma disruption as well as a seismic event. A finite element method for the calculation of the electromagnetic force induced by disruption and the structural analysis has been applied. The most serious event which is fast major disruption, is mainly considered. The eddy current reaches up to 100 MA/m(2), which induces electromagnetic force < 120 MN/m(3). The SP has been modified in order to satisfy the allowable membrane, bend and peak stress of SS316 L. Trial manufacture of a part of the SP has been done to investigate the effect of the weld on the deformation of the SP resulting from the contraction of the weld metal. The arrangement of heat sinks and coolant pipes, and graphite tiles has also been done, taking into account the long pulse operation of the JT-60SA plasma.