Actively cooled plasma facing components for long pulse high power operation

This paper reviews the development of heat removal technology for plasma facing components (PFCs) and focuses on water-cooled PFCs for near term, high power applications and the use of the tungsten (W), carbon (C), and beryllium (Be) as the preferred armor materials. There are also brief summaries of developments in helium-cooled PFCs and applications of free liquid surfaces. Water-cooled PFCs with C armor have been developed for Tore Supra, ITER, LHD and W7-X. W or Be armor is of interest for ITER and other devices. W-coatings on graphite have been tried, and mockups with “W brush” armor, developed in the USA for ITER and emulated elsewhere, have withstood thermal cycling at 25 MW/m2. Reliably joining of the armor has been a significant challenge. A shorter version of this paper was published previously in the International Toki Conference on Plasma Physics and Controlled Nuclear Fusion (ITC-10), Toki, Japan, January 18–21, 2000.