An in-situ tritium-deuterium gas-purification system for muon catalyzed fusion experiments at the RIKEN-RAL Muon facility

An in-situ tritium-deuterium gas-purification system has been constructed to produce a high-purity D-T target gas for muon catalyzed fusion experiments at the RIKEN-RAL Muon Facility. At the experiment site, the system enables us to purify the D-T target gas by removing ³He component, to adjust the D/T gas mixing ratio and to measure the hydrogen isotope components. The system is specially designed to handle the D-T gas with a negative pressure, and the maximum tritium inventory of 56 TBq (1500 Ci) is operated. The employed combination of a palladium filter and a cryotrap has demonstrated as an efficient device to purify hydrogen gas with a negative pressure. We have completed a series of muon catalyzed d-t fusion experiments at various tritium concentrations, including an experiment with a non-equilibrium D₂-T₂ target condition. The muon catalyzed t-t fusion process has also been studied using the tritium gas supplied free of ³He by the system.