Evaluation of Hydrogen Isotope Transport Performance Using Proton Conductors for Divertor Pumping System

In a DEMO fusion reactor, it is necessary to continuously extract deuterium and tritium from the unburned fuel gas under divertor panels. For the pumping system in the divertor, a new method of transferring hydrogen isotope using proton conductors has been proposed. In this study, we have constructed a new experimental setup using a proton conductor to simulate a divertor pumping system, which extracts hydrogen isotope selectively. Pellets of yttrium-doped cerium oxide and indium-doped zirconium oxide were used as proton conductors. The hydrogen partial pressure on the anode side was set at the atmospheric pressure level and that on the cathode side at 10^{2} Pa. A dc current was applied to the proton conductor cell to selectively transfer hydrogen isotopes. The experiments were conducted in the temperature range of 400 °C- 600 °C. Gas analysis of the transported hydrogen isotopes was carried out using H2 and D2 gas mixture to obtain the transport number. Based on the data obtained from these experiments, the main parameters such as the total area of the proton conductor and the operating conditions are discussed.