Abstract. An experimental procedure is developed to determine the scatter of the macroscopic toughness of brittle materials. First, samples are precracked to obtain a sharp precrack. The toughness is then determined by using a standard three-point flexural test. Digital image correlation is used to analyze displacement fields of cracked samples. Based upon the resolution and the spatial resolution of the measurement technique, a detection criterion is proposed and validated. It allows for an accurate estimate of the crack tip location so that the presence of a crack and its size at arrest can be monitored. As an example, the toughness distribution of 18 samples made of silicon carbide is evaluated. By using a simple macro-micro transition, an analysis of the scatter in toughness is related to that in strength for the material with no macrocracks.

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A parametric study is performed with the 2D FESTIM code for the ITER monoblock geometry. The influence of the monoblock surface temperature, the incident ion energy and particle flux on the monoblock hydrogen inventory is investigated. The simulated data is analysed with a Gaussian regression process and an inventory map as a function of ion energy and incident flux is given. Using this inventory map, the hydrogen inventory in the divertor is easily derived for any type of scenario. Here, the case of a detached ITER scenario with inputs from the SOLPS code is presented. For this scenario, the hydrogen inventory per monoblock is highly dependent of surface temperature and ranges from $$10^{18}$$ 10 18 to $$6 \times 10^{19}$$ 6 × 10 19 H after a $$10^{7}$$ 10 7 s exposure. The inventory evolves as a power law of time and is lower at strike points where the surface temperature is high. Hydrogen inventory in the whole divertor after a $$10^{7}$$ 10 7 s exposure is estimated at approximately 8 g.