A Rn-220 source for the calibration of low-background experiments

Abstract

We characterize two 40 kBq sources of electrodeposited Th-228 for use in low-background experiments. The sources efficiently emanate Rn-220, a noble gas that can diffuse in a detector volume. Rn-220 and its daughter isotopes produce alpha, beta, and gamma-radiation, which may used to calibrate a variety of detector responses and features, before decaying completely in only a few days. We perform various tests to place limits on the release of other long-lived isotopes. In particular, we find an emanation of <0.008 atoms/min/kBq (90% CL) for Th-228 and 1.53 atoms/min/kBq for Ra-224. The sources lend themselves in particular to the calibration of detectors employing liquid noble elements such as argon and xenon. With the source mounted in a noble gas system, we demonstrate that filters are highly efficient in reducing the activity of these longer-lived isotopes further. We thus confirm the suitability of these sources even for use in next-generation experiments, such as XENON1T/XENONnT, LZ, and nEXO.

15 pages, 9 figures

References in corpus (5)

• Dark matter direct-detection experiments
• Measurements of the ion fraction and mobility of alpha and beta decay products in liquid xenon using EXO-200
• Xenon Recirculation-Purification with a Heat Exchanger
• Search for $2\nu \beta \beta$ decay of ${}^{136}$Xe to the 0${}_1^{+}$ excited state of ${}^{136}$Ba with EXO-200
• Status of double beta decay experiments using isotopes other than Xe-136

Cited by in corpus (15)

• DarkSide-20k: A 20 Tonne Two-Phase LAr TPC for Direct Dark Matter Detection at LNGS
• First Dark Matter Search with Nuclear Recoils from the XENONnT Experiment
• DARWIN: towards the ultimate dark matter detector
• The XENON1T Dark Matter Experiment
• A Next-Generation Liquid Xenon Observatory for Dark Matter and Neutrino Physics
• The XENONnT Dark Matter Experiment
• Projected sensitivity of the LUX-ZEPLIN experiment to the $0\nu \beta \beta$ decay of ${}^{136}$Xe
• Results from a Calibration of XENON100 Using a Source of Dissolved Radon-220
• ${}^{222}$Rn emanation measurements for the XENON1T experiment
• Investigating the XENON1T Low-Energy Electronic Recoil Excess Using NEST
• The XLZD Design Book: Towards the Next-Generation Liquid Xenon Observatory for Dark Matter and Neutrino Physics
• Low-energy Calibration of XENON1T with an Internal ${}^{37}$Ar Source
• Characterization of a ${}^{220}$Rn source for low-energy electronic recoil calibration of the XENONnT detector
• Development of a ${}^{127}$Xe calibration source for nEXO
• A flexible test facility for liquid xenon detector development