HD gas analysis with Gas Chromatography and Quadrupole Mass Spectrometer
  A gas analyzer system has been developed to analyze Hydrogen-Deuteride (HD) gas for producing frozen-spin polarized HD targets, which are used for hadron photoproduction experiments at SPring-8. Small amounts of ortho-H$_{2}$ and para-D$_{2}$ gas mixtures ($\sim$0.01%) in the purified HD gas are a key to realize a frozen-spin polarized target. In order to obtain reliable concentrations of these gas mixtures in the HD gas, we produced a new gas analyzer system combining two independent measurements with the gas chromatography and the QMS. The para-H$_{2}$, ortho-H$_{2}$, HD, and D$_{2}$ are separated using the retention time of the gas chromatography and the mass/charge. It is found that the new gas analyzer system can measure small concentrations of $\sim$0.01% for the otho-H$_2$ and D$_2$ with good S/N ratios. 
T. Ohta, S. Bouchigny, J.-P. Didelez, M. Fujiwara, K. Fukuda, H.   Kohri, T. Kunimatsu, C. Morisaki, S. Ono, G. Rouille, M. ...
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