Noble gas mass spectrometry

The main focus of this lab, run with support by Eawag, is to measure the elemental and isotopic compositions of all noble gases He, Ne, Ar, Kr and Xe with high precision in terrestrial and extraterrestrial samples. Solid, liquid and gaseous samples can be analysed for their noble content. The backbone of the lab are several commercial and custom-build sector-field noble gas mass spectrometers. The instruments are mostly operated in peak-jumping mode and are equipped with Faraday-cups and Multipliers usually operated as ion counters. One mass spectrometer comprises a world-wide unique compressor source to reach very high sensitivities for He and Ne for the analysis of small or gas-poor samples. Furthermore, a variety of techniques for noble gas extraction are available, comprising UV and IR lasers, electron-bombardment crucibles reaching up to 1750 °C, an in-vacuum crusher with sieving mechanism, in-situ water degassing devices, and a unique Au-Pt “etch line” to release noble gases from precious extraterrestrial material by means of chemical dissolution at low temperature rather than extraction by heating. Another device allows the extraction of terrestrial samples for C-14 study, equipped with an all-metal system and an electron-bombardment oven. The lab also comprises an apparatus to prepare noble gas standards with very high precision.