Speed of Sound Measurement of Hydrogen Isotopologues Containing Tritium for Reference Gas Sample Verification

Accurate gas samples containing tritiated molecules are essential for the development of tritium monitoring tools and to study tritium-induced reaction dynamics. We prepared gas samples that may contain any of the six hydrogen isotopologues by manometrically mixing high-purity homonuclear isotopologues and forming the remaining isotopologues by chemical equilibration. In order to independently verify the relative isotopologue concentrations to the manometrically derived composition and thus validate the accuracy of the produced gas samples, we measured the effective speed of sound (SoS) in the gas mixtures, which are highly sensitive to small deviations in the relative molar fractions due to the large difference in the individual SoSs. We found that deviations between the manometrically derived and measured SoSs are on a 0.1% level, demonstrating the accuracy of the sample production procedure and the suitability of SoS measurements for inline composition monitoring in tritium applications.