HD gas analysis with Gas Chromatography and Quadrupole Mass Spectrometer

TL;DR

This paper presents a new gas analyzer system combining gas chromatography and quadrupole mass spectrometry to accurately measure tiny concentrations of specific gases in HD mixtures, crucial for polarized target experiments.

Contribution

The novel gas analyzer system effectively measures small concentrations (~0.01%) of ortho-H₂ and D₂ in HD gas using combined chromatography and mass spectrometry techniques.

Findings

Able to measure ~0.01% concentrations of gases

Effective separation of gas components by retention time and mass/charge

Reliable detection with good S/N ratios

Abstract

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.