Isotopic Separation Analysis of Infinitesimal Concentrations of Hydrogen Using Trace Reduction Detector

• Published in: Fusion science and technology Vol. 48; no. 1; pp. 405 - 408
• Main Authors: Kawano, Takao, Tsuboi, Naohiro, Tsujii, Hirotsugu, Asakura, Yamato, Uda, Tatsuhiko
• Format: Journal Article
• Language: English
• Published: United States Taylor & Francis 01.08.2005
• Subjects: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ABSORPTION; AIR; DEUTERIUM; HYDROGEN 1; ISOTOPE SEPARATION; MIXTURES; MONITORS; NITROGEN; OXIDES; RETENTION; THERMONUCLEAR FUELS; TRITIUM
• ISSN: 1536-1055; 1943-7641
• DOI: 10.13182/FST05-A954

A previously developed analyzer for detecting extremely small concentrations of hydrogen in air was evaluated by using it to distinguish hydrogen isotopes. The analyzer utilizes the functions of a gas chromatograph and an atomic absorption spectrophotometer and is based on the reduction reaction of mercuric oxide with hydrogen. Three test samples were used: gas mixtures containing both protium and deuterium with almost equal concentrations of about 5, 20, or 50 cm 3 /1000 m 3 diluted in nitrogen. Each measurement was repeated more than 30 times, and chromatograms were obtained for each test sample. Examination of the chromatograms showed that the retention times for the protium and deuterium could be clearly distinguished. The retention times were virtually constant and indistinguishable, independent of the concentration and repetition time. The peak areas for the protium and deuterium were also stable, independent of the repetition time. Moreover, there was a clear linear relationship between the peak areas and concentrations for both elements. These results show that the analyzer can distinguish the two hydrogen isotopes and estimate concentrations of each as small as about 5 cm 3 /1000 m 3 . They also show that it may be possible to use the analyzer to monitor tritium concentrations.