Development of force reconstruction method on EU ITER TBM based on strain measurements

One of the main objectives of the ITER Test Blanket Module (TBM) program is to acquire all relevant data and information to validate the applied codes for the relevant analyses of the corresponding breeding blanket concept. In this paper the possibility to validate electro-magnetic (EM) models and codes based on the measurement of EM forces on the TBM sets during off-normal operation, e.g. plasma disruptions, is discussed. As the direct measurement of these forces is not possible, the application of force reconstruction methods is proposed. Optical fibers strain gauges are proposed as sensor type and a genetic algorithm to optimize the sensor arrangement considering the requirements for sensor installation is described. The procedure to validate EM models and codes based on the reconstruction of modal forces is explained and criteria are defined as a maximum error of 10% in the eigenfrequencies and eigenvectors of the modal model used in the algorithm in combination with 20 sensors to allow the validation. An experimental setup and program with a simplified TBM mock-up is described that will allow a final assessment on the applicability of the method in ITER.