Abstract
We report on the first measurement of 39Ar in argon from underground natural gas reservoirs. The gas stored in the US National Helium Reserve was found to contain a low level of 39Ar. The ratio of 39Ar to stable argon was measured to be ≤ 4 × 10- 17 (84% C.L.), less than 5% the value in atmospheric argon (39 Ar / Ar = 8 × 10- 16). The total quantity of argon currently stored in the National Helium Reserve is estimated at 1000 tons. 39Ar represents one of the most important backgrounds in argon detectors for WIMP dark matter searches. The findings reported demonstrate the possibility of constructing large multi-ton argon detectors with low radioactivity suitable for WIMP dark matter searches.
Original language | English (US) |
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Pages (from-to) | 46-51 |
Number of pages | 6 |
Journal | Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment |
Volume | 587 |
Issue number | 1 |
DOIs | |
State | Published - Mar 11 2008 |
Keywords
- Cryogenic noble gases
- Dark matter
- Low background detectors
ASJC Scopus subject areas
- Nuclear and High Energy Physics
- Instrumentation