A Simplified Analytical Model for the Analysis of Magnetomechanical Dynamic Response of a Test Module in J-TEXT Tokamak

Abstract

Test blanket modules (TBMs) are key components of the ITER for the demonstration of tritium breeding. During plasma disruption, the TBMs and other in-vessel components suffer large electromagnetic forces and vibrations accompanied by a significant magnetostructural coupling effect. Aiming to evaluate the coupled vibration of a test module in J-TEXT Tokamak, a simplified analytical model was developed in this paper. The model has one degree of torsional freedom and was established by the idealization of the geometry and the confining magnetic field. The analytical solution of the model indicates that the magnetic stiffness effect is not significant for this problem, and the model gives a conservation estimation of the magnetic damping effect. To demonstrate the feasibility of the analytical model, the dynamic response of the test module in J-TEXT during a typical plasma disruption event was simulated by using an FEM numerical code of the Lagrangian sequential coupling method and was found to be in good agreement with the analytical solution. To prove the validity of the numerical model and code, the coupled vibration of a cubic block in a large constant magnetic field and a pulsed magnetic field of an electromagnet was measured by fabricating an experimental setup in a large magnet and was also calculated by using the FEM code under the experimental conditions. The measured results agree well with the numerical ones, which proved the validity of the analytical model indirectly. Due to the explicit form of the coupling term, the analytical solution gives a good reference when considering the magnetostructural coupling effect of a typical in-vessel structure in the tokamak device.