OVERVIEW

Liquid metal first wall is attractive in fusion reactor designs because of its high heat removal and self-refreshment capabilities. In liquid wall study, method of forming stable liquid flows on the front surface of blanket has to be found. In order to do this, free surface magneto-hydrodynamic (MHD) effects and flow velocity distributions of liquid metal under gravity have been studied. In our study, liquid metal flows down along ducts half-opened to face the plasma. Net electromagnetic force forms from induced eddy current interacting with the confinement magnetic field (12T) in the liquid metal flow. For liquid metal lithium (about 4cm thick), distributions of velocity along the flow direction have been obtained by combined calculations of free surface flow and electromagnetic analysis. The results show that MHD baffle might be used to get stable in front of the blanket.

Keywords: liquid first wall MHD free surface

1 INTRODUCTION

In fusion reactor designs, first walls are one kind of plasma-facing components (PFCs), which will be irradiated by high energy neutrons and other particles and work under high plasma heat flux. They should be considered carefully. Many experiments and theories have been put forward for good PFCs designs to be got. Solid first walls, which are main designs for current tokamak reactors, are most easily damaged in-vessel components. From 1998, the U.S. started the three-year program Advanced Limiter-diverter Plasma-facing Systems (ALPS) to demonstrate the advantages...