Scientists use glowing crystal core in bold experiment to catch elusive dark matter

The SABRE South Collaboration has finally published the executive summary of its Technical Design Report. 

This document outlines the full experimental setup for the SABRE South dark matter experiment, which is being installed in the Stawell Underground Physics Laboratory (SUPL) in Victoria, Australia.

The SABRE South experiment is designed to search for dark matter from the Southern Hemisphere. Its main goal is to provide independent confirmation of results previously recorded by the DAMA/LIBRA experiment in Italy. 

High-tech dark matter

DAMA/LIBRA has reported annual modulation signals consistent with dark matter, but its results remain controversial due to a lack of confirmation from other detectors. 

SABRE South aims to resolve this issue by operating under similar principles but from a different hemisphere, which can help rule out seasonal or environmental effects.

The report describes the essential components of the experimental setup. This includes ultra-pure sodium iodide crystals enclosed in custom-made copper vessels. 

These are placed inside a detector system filled with a liquid scintillator to detect light signals resulting from crystal interactions. 

An array of muon detectors surrounds the main vessel to identify cosmic ray interactions, allowing the system to distinguish between background noise and true dark matter events.

Systems that help with calibration and data collection are important.

They monitor how stable the detectors are, check if measurements are correct, and handle large amounts of data from long-term operations.

The SABRE South Collaboration includes scientists from five Australian institutions: The University of Melbourne, The University of Adelaide, The University of Sydney, Swinburne University of Technology, and the Australian National University. 

The project is part of the ARC Centre of Excellence for Dark Matter Particle Physics.

Detecting matter

Lachlan Milligan, a PhD candidate at the University of Melbourne and a contributor to the project since 2019, highlighted the value of the design report for future researchers. 

He said early-stage involvement in building the experiment provides a rare opportunity for graduate students, as most join projects after experiments have already begun taking data.

Professor Phillip Urquijo, Chief Investigator at the ARC Centre of Excellence, described the report as a major milestone. 

He said the team has prepared for this phase for nearly ten years. He added that the report reflects the depth of planning and technical development required to construct a world-class dark matter detector.

The SABRE South vessel is now transported to the Stawell Underground Physics Laboratory. 

Data collection is expected to begin by the end of 2025. If successful, the experiment could help confirm or refute one of the most persistent anomalies in dark matter research. 

It will also strengthen Australia’s role in global particle physics by providing unique data from the Southern Hemisphere.

The SABRE South project represents a long-term commitment to answering a fundamental scientific question: What is the nature of dark matter?