Electromagnetic analysis of the ITER port-mounted bolometer cameras

Abstract

This paper describes the electromagnetic analysis procedure of the ITER (upper and equatorial) port mounted bolometer cameras. The main aim of the analysis beside the evaluation of the electromagnetic forces caused by changing magnetic fields is to find out the worst load case scenario for a particular bolometer camera. For this purpose, a wide range of load case scenarios has been analyzed. The output from 2D axisymmetric code DINA is used as input to a general electromagnetic model of a 20° sector of the ITER structure, taking into account the contribution of all structural parts, in order to calculate eddy currents induced inside the bolometer components. The surrounding structure of the bolometer camera housing was modeled with particular precision in order to take the electromagnetic contributions of these parts into account as precisely as possible. To investigate the worst load case per camera type and position six representative disruption scenarios are analyzed. In a second step, the Lorentz-forces resulting from the interaction of these eddy currents with the main magnetic field are deduced. They are an essential input for the structural assessment of the camera housing. This paper discus in detail EM analysis procedures used in case of port-mounted bolometer cameras.