Simulation experimental investigation of plasma off-normal events on advanced silicon doped CFC-NS31

Fusion devices high heat loading due to off-normal events (e.g., plasma disruption, slow transients and ELMs, which can occur during a transition from detached to attached divertor operation) requires high thermal conductivity materials. Therefore, carbon fiber composites (CFCs) with high thermal conductivity are favorable. In the framework of the European Fusion Technology program, a great effort has been made to develop Si doped CFCs. NS31 is a 3D CFC containing about 8–10 at.% of silicon. The previous results showed, that NS31 poses lower chemical erosion, lower tritium retention and higher resistivity to water/oxygen reaction in comparing with undoped CFCs. Off-normal simulation experiments were performed under two conditions: (a) 700 MW/m2, 10 ms and (b) slow transient 20 MW/m2, 2 and 4 s. NS31 behaved very stable even under these extremely severe conditions. In this paper, the detailed results of simulation experiment on high heat loading due to off-normal events are presented and consequences are discussed.