Detailed structural evaluation of the TPX toroidal field magnet nose region

A detailed structural analysis of the Tokamak Physics Experiment (TPX) toroidal field (TF) cell case is presented. The investigation focuses on a section through the equatorial plane of the inboard leg, or nose region, in order to study the most restricted space in the TF cell structure. The analysis begins with a detailed electromagnetic finite element ANSYS model of the TF coil and case. Individual conductors are modeled. Forces produced by the interaction of the magnetic field and conductor currents are produced as input to the structural analysis. The model is fully parameterized which allows for multiple computer runs of various grid densities and geometries, all with the aim of obtaining well characterized stresses in the structural and insulating elements of the coil and case. The objective of the analysis is to quantify the stresses in the cell case. In addition, changes in the case wall thickness are considered to improve the stress field in the region of closure welds. The study closes with a comparison of computed and allowable stresses, including a brief summary of fatigue results, and a recommendation on the critical TF case weld location