The SABRE South Experiment at the Stawell Underground Physics Laboratory

Abstract

SABRE aims to provide a test of the signal observed by DAMA/LIBRA through two separate detectors that rely on joint ultra-high NaI(Tl) purity crystal R&D activities: SABRE South at SUPL Australia and SABRE North at LNGS Italy. SABRE South is designed to disentangle seasonal and site-related effects from the dark matter-like modulated signal. Ultra-high purity crystals are immersed in a liquid scintillator veto, further surrounded by passive shielding and a plastic scintillator muon veto. Significant work has been undertaken to assess and mitigate background from the detector materials, and to understand the performance of both the crystal and veto systems. SUPL is a newly built facility located 1024 m underground in Australia. SABRE South is currently being assembled and will be completed in 2025, with first subsystems already installed in SUPL. This proceedings will report on the general status of the SABRE South assembly, its expected performance, and the design of SUPL.

Figures (3)

• Figure 1: Left: A labelled render of the SABRE South detector system, including shielding. Left of the detector is an enlarged version of the crystal enclosure, labelling its key components. Right: The total experimental background for SABRE South as a function of energy.
• Figure 2: Left: The SABRE South detectors assembled for flux measurements in SUPL. Right: The total muon flux as a function of water equivalent depth. The muon flux for SUPL is relatively on par with Boulby and Kamioka. Labs with mountainous overburden are shown in the blue shaded region.
• Figure 3: Left: Exclusion/discovery power of SABRE South given 50 kg of crystals and a total background of 0.72 cpd/kg/keV$_{\rm ee}$. Right: Years to 5$\sigma$ discovery as a function of target mass and total background, where the same discovery power is possible with a lower target mass given a lower total background, as discussed in Sec. \ref{['sec:det']}.