Search

The ITER WAVS (visible and infrared Wide Angle Viewing System) provides measurements of surface temperature for the plasma facing components by infrared thermography. One of its most important roles of WAVS is to protect the plasma facing components from damage. It also takes images of the plasma visible spectral range emission. The WAVS diagnostic consists of 15 views distributed in four equatorial ports (3, 9, 12 and 17), and it will contribute to Machine protection, Basic control and Physics analysis. The final design of the WAVS system in the equatorial port 12 (EP12) includes three lines of sight (LoS) that have to installed for ITER first plasma. This paper is focussed on the final design for the opto-mechanical ex-vessel components in equatorial port 12 (EP12). The most important function of the ex-vessel optics is to relay the image produced by the Port Plug optics at the vacuum window, up to the detectors placed at the backend of the optical chain in the Port Cell, while keeping the required performance. The image relays through the Interspace, Bioshield and Port Cell covers around 10 m in length before reaching the cameras. The ex-vessel optics is arranged in several optical modules, assembled on the EP12 support structures, i.e. Interspace Support Structure (ISS) and Port Cell Support Structure (PCSS). A detailed description of the opto-mechanical design that supports the optical modules, including the alignment capabilities, will be presented in the paper. Moreover, the assembly and alignment strategies planned for the ex-vessel subsystems, taking into account all constraints imposed on the site, are also described in the paper. [ABSTRACT FROM AUTHOR]

The ITER Visible/Infrared Wide Angle Viewing System (WAVS) is a machine protection optical diagnostic that is being developed for ITER. The first two ex-vessel components of WAVS are the Optical Hinge (OH) and Optical Relay Unit (ORU) and both share a common support structure. Equatorial Port 12 (EP12) WAVS should be operational for the first plasma and its facing its Final Design Review (FDR). It is being developed by the Consortium constituted by CEA, CIEMAT, INTA and Bertin Technologies through a Grant Agreement financed by F4E. To compensate vacuum vessel vertical displacements respect to the building during operation, an Optical Hinge (OH) will be placed at the beginning of the ex-vessel area for each Line of Sight (LoS). Each OH is formed by a pair of mirrors one of which is moveable using a piezoactuator. The OHs are attached to the common support which is, in turn, fixed to the Interspace Support Structure. To assure the optical performance, the common support structure has to withstand operational loads with low deviation and tilt. In addition, the structural integrity of the common structure has to be maintained in case of seismic or accidental loads as it is classified as a Safety Relevant component. This work exposes the analyses performed to face the FDR of ex-vessel WAVS in EP12. It comprises the structural analyses performed by CIEMAT for the OH ORU common support structure to assure its integrity according to RCC-MR Code and the detailed model of one OH LoS to check also the diagnostic optical requirements. [ABSTRACT FROM AUTHOR]

• 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]