Status of Plasma Facing Material Studies and Issues toward DEMO

Abstract

This review paper presents status of research activity of plasma facing materials, mostly tungsten and critical issues towards DEMO reactors. A helium effect on tungsten surface morphology and its impact on fusion reactors and a pulsed heat effect to tungsten are briefly summarized. For DEMO, effects of steady-state operation and heavy neutron irradiation are important subjects to investigate. Present understandings on these are briefly summarized. Finally, issues of helical system towards DEMO will be discussed.