Noble Gas Laboratory

Noble gases, helium, neon, argon, krypton and xenon, are extracted from geological samples by a resistively-heated, double vacuum tantalum furnace, enabling to heat as much as 2100°C, by an air actuated-type vacuum crusher, or by a diode laser heating system. After extraction, the gases are cleaned of active species (such as H2O, CO2, H2 etc.) by exposure to a series of getters. They are then cryogenically separated from each other, and sequentially inlet to a high sensitivity noble gas mass spectrometer for isotopic and abundance determinations. The ANU noble gas laboratory is especially focused on research on noble gas mantle geochemistry and cosmogenic noble gas surface exposure dating.

Helix-MC is a 350mm 120 degree extended geometry ion optics high resolution multi-collector mass spectrometer for the simultaneous analysis of Neon, Argon, Krypton and Xenon (five isotopes). Detector array is designed with a fixed axial detector and up to 2 adjustable high mass (High1 and High2) and 2 adjustable low mass (Low1 and Low2) detectors. Each detector is equipped with a new Faraday/ion counting multiplier CFM (Combined Faraday and Multiplier) detector. Mass resolution and mass resolving power on the High2, Axial and Low2 detectors of the Helix-MC installed at the ANU are up to1,800 and 8,000, respectively. The noble gas laboratory at the ANU is the first recipient of the Helix-MC mass spectrometer, delivered in early 2013. It is anticipated that it will become fully operational in 2013.

In addition, the noble gas laboratory maintains the VG5400 noble gas mass spectrometer (with mass resolution of 550) and its dedicated gas handling system, which is fully operational for sample analyses.