📋 Tender Overview
The SABRE collaboration is incredibly grateful to ANSTO and its Australian Synchrotron for hosting the solvent tank while the Stawell Underground Physics Laboratory is under construction in 2021 said from AProf Phillip Urquijo University of Melbourne one of the Chief Investigators of the ARC Centre of Excellence for Dark Matter Particle Physics.The event veto function of the organic solvent known Linear Alkyl Benzene LAB is a key feature that guarantees the background levels of SABRE will be considerably lower than northern hemisphere experiments.SABRE the first deep underground dark matter experiment in the Southern Hemisphere is expected to provide a definitive test of the DAMALIBRA result within three years of commencing operation said Professor Elisabetta Barberio Director of the ARC Centre of Excellence for Dark Matter Particle Physics. It will be the first experiment located in the Stawell Underground Physics Laboratory SUPL which is currently under construction in the Stawell Gold Mine in Western Victoria.The SABRE Dark Matter DetectorSABRE stands for Sodium iodide with Active Background Rejection. The detector see schematic below will consist of approximately 100 tons of steel and polyethylene shielding surrounding a 2.6m by 3.1m vessel made from radioactive-free pure steel containing the liquid scintillator.Immersed in the 12 tonnes of liquid scintillator are the ultra-pure sodium iodide detector crystals which are instrumented to observe dark matter interactions.Photomultiplier tubes PMTs light detectors capable of observing single photons are independently coupled to both the sodium iodide crystals and the liquid scintillator in order to sense the light emitted when different types of radiation interact with these detector elements.Since dark matter interacts so rarely with normal matter any events where both the liquid scintillator and the sodium iodide simultaneously observe radiation can be rejected as this will not be a real dark matter event.The scintillation liquid provides an active veto to eliminate background radiation which will reduce the background count rate significantly over SABREs predecessor the DAMALIBRA experiment located in Italy.To potentially detect dark matter particles the detector must be protected from all other sources of radiation as far as possible. In SUPL the SABRE detector has three layers of protectionAn underground location situated over 1km underground in the Stawell Gold Mine where almost all cosmic ray radiation will be eliminatedThe detector itself will be heavily shielded by around 100 tonnes of steel and polymer shieldingThe liquid scintillator veto system to detect and eliminate false signalsThe scintillator is based on an organic solvent Linear Alkyl Benzene LAB mixed with fluorescent chemicals.The ultra-pure LAB has been specially manufactured by the supplier to the JUNO neutrino experiment through a collaboration with the Institute of High Energy Physics in Beijing.The transportation tank is stainless steel cleaned with de-ionised water and purged with nitrogen to ensure no exposure to oxygen.
