Optimization Of Ferromagnetic Blocks Distribution And Restrain Analysis Of TFC Ripple

ITER (International Thermonuclear Experimental Reactor) project is a important procedure to application from the experimental of thermonuclear fusion reaction, it provides an important foundation for the research of nuclear fusion reaction. In thermonuclear fusion reactor, the toroidal field coil (TFC) system consists of18D-shaped coils, and the toroidal angle between two adjacent coils is20degrees, the weaken of magnetic field between two adjacent coils is caused by the discontinuity. This phenomenon will cause energy loss from plasma, including alpha particles and other high-energy particles. Energy balance will be broken caused by the energy loss, and it have a bad influence to limit the loss of thermal load. So how to control the inhomogeneity of toroidal magnetic field has become an important problem in the design of structure.Contrapose the inhomogeneity problem of magnetic field, this paper introduces the concept of IWS and the magnetic ripple first. The author adopted a method of adding ferromagnetic blocks which with a certain quantity and space distribution to IWS to reduce the toroidal field ripple problem, this method has been used in many TOKAMAK device widely.This paper firstly introduced conceptual model of IWS, structural design criteria, materials and the detailed design process of IWS, introduces the development situation and its manufacturing process. Author builded a complete finite element model, applying the plasma excitation, toroidal magnetic excitation and poloidal field excitation, used a method of adding ferromagnetic blocks into neutron shielding layer, and the toroidal field ripple was simulated. The results show that the inhomogeneity of toroidal magnetic field around the plasma was controlled effectively, and the peak of magnetic field ripple in the area of plasma edge was reduced to under0.4%, verified the rationality of neutrion shielding blocks distribution in the existing model. In addition, considering the influence of electromagnetic force to neutron shielding blocks affected by magnetic field, this article calculated the electromagnetic force of ferromagnetic blocks in the magnetic field, and get a accurate result, it verified the stability of existing structure, provided a reference to the design of ITER neutron shielding structure.