ELECTROMECHANICAL ANALYSIS OF THE ITER ION CYCLOTRON ANTENNA STRUCTURE AND COMPONENTS

3D finite-element models of the ITER ion cyclotron RF antenna assembly have been implemented in order to perform electromagnetic and stress analyses and to calculate the applied electromagnetic loads, torques and forces on the antenna structure during plasma disruption events. The electromagnetic analysis has been carried out as follows: first the antenna outer structure is analyzed (support structure, neutron shield and Faraday shield), the magnetic field variation penetrating the outer structure is then computed and applied as forcing field to the antenna inner structure (four port junction, coaxial lines and straps). The stress analysis is carried out, for both the inner and outer structure, by computing in any element the cross product of the eddy current distribution with the local static magnetic field and by deriving stresses and deformations. Results of the analyses have shown that mechanical stresses are below the allowable limits in all the components of the antenna except the Faraday shield which needs some design improvements because of the very large displacements and stresses.