Precision Measurement of the Specific Activity of ${}^{39}$Ar in Atmospheric Argon with the DEAP-3600 Detector

Abstract

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 $\pm$ 24) kg of liquid argon distilled from the atmosphere to search for dark matter. This detector with very low background uses pulseshape discrimination to differentiate between nuclear recoils and electron recoils and is well-suited to measure the decay of ${}^{39}$Ar. With 167 live-days of data, the measured specific activity at the time of atmospheric extraction is [0.964 $\pm$ 0.001 (stat) $\pm$ 0.024 (sys)] Bq/kg${}_{\mathrm{atmAr}}$ which is consistent with results from other experiments. A cross-check analysis using different event selection criteria provides a consistent result.

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• Measurement of the specific activity of Ar-39 in natural argon
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Cited by in corpus (7)

• The science and technology of liquid argon detectors
• Application of the Most Frequent Value Method for ${}^{39}$Ar Half-Life Determination
• Demonstration of new MeV-scale capabilities in large neutrino LArTPCs using ambient radiogenic and cosmogenic activity in MicroBooNE
• Estimation of Ru-97 Half-Life Using the Most Frequent Value Method and Bootstrapping Techniques
• Optimizing Sensor Data Interpretation via Hybrid Parametric Bootstrapping
• Direct Measurement of the ${}^{39}$Ar Half-life from 3.4 Years of Data with the DEAP-3600 Detector
• Study of the energy calibration of the DEAP-3600 detector using ${}^{22}\mathrm{Na}$ source data and simulations