Synthesis and hydrogen plasma interaction of model mixed materials for fusion

• An original method was used to create materials (W/C/Mg) related to fusion context.
• The size and the composition of mixed materials can be controlled by milling time.
• Resurgence of magnesium is observed under hydrogen plasma exposure.
• These materials may ad/ab-sorb up to 20 TBq of trapped tritium per kg of W dust.

Samples of mixed materials relevant to fusion (W/C/Mg, where Mg is a chemical stand-in for Be) have been synthesized by planetary ball milling. We explore here W-rich compounds, and investigate their structural and physico-chemical properties, both before and after hydrogen plasma exposure. After presenting the synthesis method experimental results are detailed: clear differences between incorporation of magnesium and/or carbon into a tungsten matrix are observed, as reflected in the specific surface area of the samples and their lattice parameters. Indeed, specific surface area decreases with increasing Mg content but increases with C content. The same trend is seen for the lattice parameter. A particular effect seen after hydrogen plasma exposure is attributed to the presence of magnesium which may also occur in the presence of beryllium.