New fusion reactor lining shows improvements

Science : The new tungsten and beryllium lining installed last year at the Joint European Torus (JET) fusion reactor in Culham, England, has experienced significantly less erosion and fuel absorption than the lining used on earlier reactors. That is promising news for ITER, the international prototype fusion energy reactor under construction in Cadarache, France, which will have a similar lining. Both JET and ITER are designed to use electromagnetic fields to contain a plasma of deuterium and tritium. However, because the plasma is unstable, it sometimes makes contact with the walls of the reactor. When that happens, the plasma can cool and erode the lining material. JET’s previous, carbon-lined wall absorbed significant amounts of tritium, which could destabilize the plasma when it later escaped from the carbon. By minimizing the amount of fuel absorption, the researchers believe it will be easier to maintain a stable plasma.