Precision measurement of the specific activity of $$^{39}$$Ar in atmospheric argon with the DEAP-3600 detector

Journal article

The specific activity of the $\beta $ decay of $^{39}$Ar in atmospheric argon is measured using the DEAP-3600 detector. DEAP-3600, located 2 km underground at SNOLAB, uses a total of (3269 ± 24) kg of liquid argon distilled from the atmosphere to search for dark matter. This detector is well-suited to measure the decay of $^{39}$Ar owing to its very low background levels. This is achieved in two ways: it uses low background construction materials; and it uses pulse-shape discrimination to differentiate between nuclear recoils and electron recoils. With 167 live-days of data, the measured specific activity at the time of atmospheric extraction is (0.964 ± 0.001$_\textrm{stat}$ ± 0.024$_\textrm{sys}$) Bq/kg$_\textrm{atmAr}$, which is consistent with results from other experiments. A cross-check analysis using different event selection criteria and a different statistical method confirms the result

Authors: Adhikari, P; Ajaj, R; Alpízar-Venegas, M; Amaudruz, P-A; Anstey, J

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: SpringerOpen
• Journal: The European Physical Journal C
• Volume: 83
• Issue: 7
• Pages: 642
• Publication date: 2023-07-20
• DOI: 10.1140/epjc/s10052-023-11678-6
• EISSN: 1434-6052
• ISSN: 1434-6044
• Language: English
• Keywords: Computer science; Analytical Chemistry (journal); Physics; Algorithm; Chemistry; Argon; Atomic physics; Chromatography