SABRE South is a DM direct-detection experiment, designed to search for proposed DM candidate particles known as WIMPs, by means of direct, physical interaction between the hypothesised particles and the detector itself.

It is one of a pair of experiments- SABRE South and SABRE North (in the northern hemisphere)- that are intended to be able to distinguish possible local and/or seasonal influences in their data from true, location-independent signals from DM particles that should be detected in the same way at both sites.

Design and construction of such an experiment is a significant undertaking, involving expertise in numerous fields, including software development, electronics, radiation physics, theoretical physics, materials science, mechanical engineering, mining engineering, and more.

The heart of the experiment is the detector vessel itself; and at its core are the sodium-iodide crystals. It is the substance of these crystals which (we think) will interact with WIMPs, producing a burst of light which will be picked up by sensitive detectors attached to the crystals.

That’s the simple part…

Surrounding the detector modules is a large stainless steel vessel, containing a large volume of liquid scintillator (known as linear alkylbenzene, or LAB), a material which will give off light when certain particles enter it. The detector crystals are embedded in this volume of LAB, but are isolated from it, being held within enclosures made from high-purity copper. The job of the LAB is to act as a veto for light flashes detected by the detector crystals; it allows us to distinguish what we expect as true DM-produced signals in the crystals from other signals caused by unwanted background sources.

(A DM event should produce a flash only within the crystal; background events should produce flashes either in the veto alone, or in both the veto and the crystal simultaneously.)

And for further protection from undesirable interference, the entire veto vessel itself is surrounded by a shield of steel and plastic, and placed about a kilometre below the ground.

And to keep all of this running, the veto vessel needs electrical and gas supplies, and outgoing signal cables leading to the measuring equipment. It also has monitoring sensors, both for safety and for maintaining stable operating conditions.

All of this equipment is interfaced to software for hardware control and monitoring, environmental monitoring, and, of course, the precious signals from the crystal modules which may carry evidence of a DM WIMP crashing into the crystal lattice…

Further afield, there also is custom-developed software for data transfer, storage and analysis… not to mention the very great effort put into software simulations to ensure that the equipment will operate as hoped, and in an optimal manner.

So while the basics of the experimental method may be experessed quite concisely, to get the whole enterprise working is a long, involved and painstaking process.

Please explore the other pages in this section for further information.