The first application of 39Ar Accelerator Mass Spectrometry (AMS) at the ATLAS facility of Argonne National Laboratory was to date ocean water samples relevant to oceanographic studies using the gas-filled magnet technique to separate the 39K- 39Ar isobars. In particular the use of a quartz liner in the plasma chamber of the electron cyclotron resonance ion source enabled a 39K reduction of a factor ∼130 compared to previous runs without liners, and allowed us to reach a detection sensitivity of 39Ar/Ar = 4 × 10 -17. In order to improve this sensitivity and allow the measurement of lower ratios, higher ion source currents and a lower overall 39K background are necessary. This paper summarizes our efforts to investigate new methods combining low level potassium cleaning techniques with the use of ultra-pure aluminum liners in the plasma chamber of the ion source. The aim of the study was to improve by 1-2 orders of magnitude the 39Ar detection sensitivity required in the selection of ultra-pure materials for detectors used in weakly interacting massive particle dark matter searches.
|Original language||English (US)|
|Number of pages||7|
|Journal||Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms|
|State||Published - Jul 15 2012|
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics
- Ion source