Low pressure fusion exhaust gases separation

Plasma enhancement gases (PEGs) (such as: nitrogen, neon, argon and other inert gases) are injected into the plasma of several tokamaks in order to reduce the power load over the plasma facing components. The exhaust gas in the tokamak demonstration reactor (DEMO) consists of more than 90% of unburned fuel gas (D and T) and the remaining part will be He, PEGs and impurities. In DEMO reactor it is foreseen to recover the fuel gas and PEGs. The research focuses to remove the He from fuel gas and PEGs from fusion reactor. For this purpose, six commercial ceramic membranes have been tested at a permeation apparatus built at ENEA Casaccia laboratories. Single gas permeances for H2, He, Ar and air were measured with a pressure drop across the membranes between 10 Pa up to 100 kPa at room temperature. The selectivities found are low except for the 0.5 nm pore size membranes. The membranes have been supplied by Ceramiques Tecniques et Industrielles (CTI SA, France).