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• 3D ANSYS Maxwell FEM model developed for the EM analysis of the IAM at FDR level. • ISS modelled to calculate the flowing eddy currents between IAM and structure. • Found presumed convergence errors in sharp inner boundary corners of Maxwell models. • Calculated IAM forces are not design driving so do not compromise the final design. The ITER Visible and Infrared Wide Angle Viewing System (WAVS) is a diagnostic aiming to optically monitor the tokamak first wall and divertor for machine protection, plasma control and physics analysis. The Interspace Afocal Module (IAM) is a refractive optical system, being one of the WAVS components located in the Interspace area. In order to assure the optical performance, the IAM has to withstand all the relevant loads defined for the Final Design, including the electromagnetic (EM) loads developed in the Interspace area under EM events. Volumetric forces during transient EM events arise from the interaction of the background magnetic field with the eddy currents induced in the conductive components when they experience time-varying magnetic fields. In case of Category III and IV loads, including load combinations with certain Major Disruption and Vertical Displacement Event cases, the IAM integrity has to be ensured since its structure is classified as Safety Relevant. The EM volumetric loads are calculated through a 3D Finite element model and will serve as inputs for the later structural analysis. The paper summarizes the EM analysis of the IAM, performed by CIEMAT, to validate its Final Design. [ABSTRACT FROM AUTHOR]

This study shows the development and performance assessment of a novel set-up that enables the research of structural materials for fusion reactors, by making possible simultaneous application of temperature (up to 450 °C) and magnetic field (close to 0.6 T) during irradiation experiments. These aspects become critical as structural materials in fusion reactors are exposed to intense radiation levels under the presence of strong magnetic fields. Moreover, material microstructure could be modified by radiation-induced propagating defects, which are thought to be sensitive to magnetic fields. The device has three main components: magnetic closure, sample holder with integrated heater, and radiation shield. It is provided with a thermal shield to prevent other elements of the device to heat up and fail. A mapping of the magnetic flux in the region where sample and heater are located has been modeled by finite elements simulation software and correlated with magnetic measurements. [ABSTRACT FROM AUTHOR]

The JT-60SA superconducting tokamak is being constructed under dual projects, the EU-JA international collaboration framework and Japanese national programme. To suppress magnetic field error to less than 0.01% with respect to the toroidal magnetic field for good confinement of plasma, QST has developed a precise onsite assembly technology of tokamak components such as vacuum vessel (VV) and toroidal magnetic field coils (TFC) with size of over 10-m scale. Prior to an onsite assembly, the assembly process is carefully simulated in a three dimension CAD model, through which the location and number of the reference points for the assembly are evaluated to determine each component position. In the onsite assembly, the tokamak components are positioned by measuring with the laser tracker of a 0.5 mm spatial resolution and assembled by adjusting with shims and splice plates. The onsite assembly of the VV 340° sector has been succeeded in an allowable accuracy of +8/−4 mm with the 10 m diameter by welding sectors, each of which was circumferentially segmented and manufactured by taking into account the deformation due to the welding. The remaining 20° sector will be installed after the TF coils installation. The metrology developed for the onsite assembly of the JT-60SA is expected to be applicable to ITER whose size is the double of JT-60SA. [ABSTRACT FROM AUTHOR]