Mechanical Pre-Compression System of the JT-60SA Central Solenoid

The mechanical loading technology has been developed for the pre-compression of central solenoid for the tokamak device of JT-60 super advanced (JT-60SA) being constructed in Japan. Four central solenoid modules were manufactured one by one, then 4 modules were stacked. The pre-compression were conducted to bind stacked 4 modules by support structure called tie-plate as a final process of the central solenoid manufacturing. The pre-compression jigs were designed by using the finite element analysis taking into account of plastic deformation of the jigs and the tie-plate. The pre-compression was performed using developed jigs. The hydraulic jacks and pumps were separately installed to the each tie-plate to control the pre-compress load individually. Since the pre-compress load changed by insulation creeping after initial loading, additional shims were inserted for the tie-plate with small load. Finally, pre-compress load of all tie-plate became within the target range. These results indicate that the pre-compression has been successfully completed using the developed jigs. In this paper, the design and analysis of the pre-compression jigs and the result of the pre-compression are reported.