Design of the Horizontal Preload System for the Toroidal Field Coils of HL-2M Project

The HL-2M tokamak, which is being built at the Southwestern Institute of Physics, is considered one of the most important short-pulse devices for future fusion research in China. The design criterion of the HL-2M specifies the demountable joints for the toroidal field coils (TFCs) due to the assembly requirements. A horizontal preload is needed to keep a good electrical conductance for the joint of each coil. In order to assure the appropriate preload to be exerted on the TFCs under different operation conditions and to provide the preload at 40 locations simultaneously, the horizontal preload system of the HL-2M tokomak has been developed. In this technical note, the design of this system is presented in detail. Finite element analysis is applied to evaluate the design. To validate the assembly and the performance, a prototype of the actuator has been manufactured and tested to finalize the design for fabrication.