Evaluation method of magnetic damping effect for fusion reactor first wall

An evaluation method of the magnetic damping effect and a method to determine the conditions for a reduced scale magnetic damping test of fusion reactor first wall are described. The coupling intensity parameter is used for the evaluation method because it has the potential to evaluate the magnetic damping effect. The thickness and the steady magnetic field required in the reduced tests are obtained to maintain two parameters unchanged, namely the coupling intensity parameter and the ratio of time constants of eddy current and structure, using finite element analysis and the solution of the coupled eigenvalue. To verify the scaling method, experiments and numerical analyses of a plate are performed for various scale factors. Good agreement between the displacement responses of the original and reduced configurations is obtained. The steady magnetic field of the reduced scale test can be decreased using copper or aluminum alloy instead of austenitic stainless steel. (C) 1998 Elsevier Science S.A. All rights reserved.