Rapid analysis of impurity components and H₂ and D₂ in helium by micro-gas chromatography

It is necessary to establish a high-precision analytical method of Micro-Gas Chromatography (μGC) for achieving the rapid detection of impurity components in process gas of Tritium Plant in Fusion Reactors with a secure and stable operation. The separation of impurities rely on capillary column of molecular sieve and PLOT-U, with the concentrations were 1.0%, 5.0% and 10.0% of impurities in standard gas and the application of Micro Thermal Conductivity Detector (μTCD) in high purity helium. After optimizing the measurement parameters, with the column temperature of MS 5A and PLOT U were 120 ℃ and 60 ℃ and the column pressure was 40 psi and 30 psi, respectively, and the injection time was 255 ms, the studies have shown that the separation of (0₂), N₂, CH₄, CO and CO₂ with different capillary columns achieved in 160 s with high column efficiency and good repeatability. In the meantime, the resolution of each other was far higher than 1.5, which could achieve complete separation. The separation of H₂ and D₂ in high purity helium with cryogenic capillary column of Al₂ O₃, which was modified by MnCl₂ with dynamic coating. It explained that the separation of hydrogen and deuterium with a shorter time less than 160 s, and the resolution between H₂ and D₂ was in excess of 2.0, which could achieve complete separation with high column efficiency and good repeatability. It can be applied to the measurement of impurities in Tokamak Exhausting Processing System (TEP), Isotope Separation System (ISS) and Storage and Delivery System (SDS), which could know about the distribution of tritium and ensure safety from the special environment. (authors)