According to a press release from Australia’s Nuclear Science and Technology Organization (ANSTO), the Stawell Below Physics Laboratory has been transformed from a gold mine that is over a mile (kilometer) underground in Victoria to study dark matter.
85 percent of the mass of our universe is thought to be made up of dark matter, an invisible element that is virtually undiscovered by humans. Scientists have been developing dark matter detectors to learn more about it, and one of the “most sensitive” detectors has produced some critical findings.
One does not simply stop with one set of data, as is the case with everything in science. It must be both repeatable and verifiable, which necessitates the construction of additional detectors. The SABRE Dark Matter Detector is one such detector, and it is located in the recently opened underground lab.
Dark matter detector SABRE
Sodium iodide with Active Background Rejection is known as SABRE. The detector consists of a jar that is built of radioactive-free pure steel and measures 8.5 feet by 10.1 feet (2.6 meters by 3.1 meters). 13.22 tons (12 tonnes) of liquid scintillator—a substance that transforms high-energy radiation into visible light—are included inside. Linear Alkyl Benzene (LAB), an organic solvent, serves as the foundation for the scintillator, which is composed of fluorescent compounds.
Ultra-pure sodium iodide crystals are essential for detecting dark matter interactions and are submerged inside the liquid scintillator. The sodium iodide crystals and scintillator liquid have been connected with photomultiplier tubes (PMTs), devices that can even detect a single photon of light, to enable this detection.
Researchers are aware that interactions between dark matter and ordinary matter are uncommon. Any light detection that occurs in both the crystals and the scintillator liquid will therefore be disregarded. The scintillation liquid will also function as an active veto because it reduces background radiation, according to the news announcement. This is a significant advancement over SABRE’s predecessor, the Italian DAMA/LIBRA lab, which was charged with finding dark matter.
Security measures for the dark matter detector
The researchers have added numerous levels of security on top of the detector’s built-in characteristics to shield it from radiation coming from other sources. The lab’s underground location is one of them.
The detector is located in an area formerly a gold mine, so cosmic radiation cannot affect it. A research hall measuring 108 feet (33 meters) long, 32 feet (10 meters) wide, and 40 feet (12.3 meters) high houses the setup as well. According to the news release, around 4,700 cubic meters of rock were removed from the site for the laboratory’s construction.
Around 110 tons (100 tonnes) of steel and polymer shielding surround the detector itself, which is well shielded.
“Our knowledge of the dark matter has been lacking for far too long. The chief investigators will have confidence that any particles they identify are not something else after we remove background radiation “According to the news announcement, Richard Garrett, Senior Advisor at ANSTO.
In addition to investigating the dark matter, ANSTO intends to use the facility for sensitive environmental sample measurements and to look at how biological systems grow in the absence of background radiation.
Dark matter is still a mystery to us, and learning more about it could potentially contradict our current understanding of how the universe works.