A proposed method for foil set qualification for multiple foil activation measurements in the TBMs

Abstract

The neutronic measurements in the ITER Test Blanket Modules (TBMs) aim at the determination of several physical quantities such as tritium production rate, heat load, and neutron spectrum, which are difficult to measure inside the hermetic zone by active detectors. For this reason activation detectors (foils) are planned to be used. The measurement circumstances, such as the irradiation time and the accessibility of the foils, highly depend on the detailed design of the TBMs and are not yet completely specified. Therefore, the flexible design requires an objective qualification method to select the optimal foil set for an actual experiment. The qualification method presented in this paper assigns a quality factor to each foil set. This factor depends on the orthogonality of the cross sections, the energy range covered by the foils and the discreteness of the energy range. A computer code has been developed to calculate the quality factor based on a calculated neutron spectrum and cross section data available in the nuclear data libraries. This study has been made in the framework of the Work Package No. 5 (measurement techniques development for breeder blankets) of the Breeding Blanket Developments for Fusion Reactors (EUROBREED) Goal Oriented Training Project supported by EFDA.