Rotating liquid blanket for a toroidal fusion reactor

Abstract

A novel blanket concept is presented for toroidal geometry in which many of the limitations imposed by a first wall are avoided by not having a first wall in the usual sense. The blanket consists of a rapidly rotating, low-vapor-pressure liquid that has a sharp boundary with the vacuum region. Nozzles inject a continuous layer of cool liquid on the inner surface. The noncentricity of the plasma is maintained so that the plasma scrape-off region intersects the rotating liquid in a localized region. This noncentricity allows sufficient space so that the scrape-off plasma layer will not bombard the nozzles, which penetrate through the rotating liquid. This liquid “first wall” is bombarded by the plasma, resulting in heat deposition, sputtering, and evaporation during the short time before the exposed liquid is covered by fresh, cool liquid from the nozzles. The advantages of this reactor concept appear to be very high wall loadings (speculated to be over 10 MW/m2) and long component lifetime, both crucial economic factors. The nozzles are designed for easy replacement. The reactor's disadvantage is its enormous potential for plasma contamination by impurities.