On structural analyses of the ITER vacuum vessel bolometer camera housing conceptual design

Abstract

The ITER bolometer provides an absolutely calibrated measurement of the radiation emitted by the plasma, which is a part of the total energy balance. The development is especially challenging because of the extreme environmental conditions within the vacuum vessel (VV) during plasma operation. The bolometer has to guarantee reliable measurements within an environment characterized by high neutron flux as well as temperatures exceeding 200°C. In addition to the thermal loads, the bolometer body is exposed to the mechanical loads caused by electromagnetic forces during transient events of plasma disruption. This paper describes a possible procedure for a structural analysis of the bolometer camera body. To examine all-important structural properties of the bolometer body, a multiple nonlinear finite element model based on a CAD conceptual design has been generated. Subsequently, a transient mechanical analysis has been performed using the finite element code ANSYS. A general electromagnetic model, taking into account the contribution of all structural parts and electromagnetic loading starting with the DINA code, generated the input for the analysis. From the wide range of DINA results, the worst-case load scenario has been chosen. The results of the structural analysis regarding the camera housing structural integrity are presented and discussed here.