Electromagnetic Optimization and Preliminary Mechanical Analysis of the CFETR CS Model Coil.

The central solenoid model coil of China Fusion Engineering Test Reactor consists of two modules: 1) the inner module made of Nb3Sn and 2) the outer module made of NbTi. This paper describes an optimization procedure for the electromagnetic design of the model coil by means of a Fortran code written for this purpose. The target of the optimization was the reduction of the length of the Nb3Sn cable-in-conduit conductor, needed to produce a peak magnetic field of 12 T. The optimization constraints are: 1) the maximum magnetic field on the NbTi module should be lower than 6 T and 2) the unit length of one Nb3Sn conductor should be shorter than 1 km. Based on the electromagnetic optimization, the engineering scheme of the model coil is determined. The feasibility of the engineering scheme is investigated using ANSYS finite element code. Accordingly, a mechanical analysis of the structure under the Lorentz force at 4.5 K is performed. The analysis results indicate that the present design is reasonable and fulfills the design requirements. [ABSTRACT FROM AUTHOR]