Summary of Recent Experimental Findings

4 Summary of Recent Experimental Findings General Remarks 

Tritium retention mechanisms are reviewed in various papers (e.g., [1, 73] for C-based materials, [1, 74, 75] for beryllium and [1, 76] for tungsten). A qualitative summary of the retention and removal characteristics of the plasma facing materials considered for ITER is shown in Table 12.4 [76]. 

Co-deposition of tritium with carbon is potentially the major T repository for ITER even if the use of carbon is minimized to the divertor strike plates. Retention by other mechanisms is expected to be low and to contribute only marginally to the in-vessel tritium-uptake (Sect. 12.4). For this reason the focus here is on some recent experimental findings associated with ( ) carbon erosion and deposition patterns in existing tokamaks, ( ) hydrocarbon film formation in areas of the divertor hidden from the plasma, and (in) mixed-material effects. 

Identification of Carbon Sources and Sinks in Existing Tokamaks 

Most of the carbon-clad divertor tokamaks consistently show a robust flow of carbon to the inboard divertor leg, which is always subject to deposition, 

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