The Stawell Underground Physics Laboratory (SUPL) is a laboratory 1 km deep in the

Stawell Gold Mine The Stawell Gold Mine (SGM) is a gold mine located in the town of Stawell, Victoria. The current site was established in 1981, however mining has occurred on and around the site since the town was established in the mid 19th century. The mine reac ...

, located in Stawell,

Shire of Northern Grampians The Shire of Northern Grampians is a local government area in the Wimmera region of Victoria, Australia, located in the western part of the state. It covers an area of and in June 2018 had a population of 11,431, having fallen from 12,087 in 200 ...

Victoria Victoria most commonly refers to: * Victoria (Australia), a state of the Commonwealth of Australia * Victoria, British Columbia, provincial capital of British Columbia, Canada * Victoria (mythology), Roman goddess of Victory * Victoria, Seychelle ...

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

. Together with the planned

Agua Negra Deep Experiment Site (ANDES) The Agua Negra Deep Experiment Site (ANDES) is a project for the construction and operation of an underground laboratory in the Agua Negra Tunnel, between Argentina and Chile. Argentina, Brazil, Chile, Mexico are involved in this project and are al ...

at the Agua Negra Pass, it is one of just two underground particle physics laboratories in the Southern Hemisphere and shall conduct research into

dark matter Dark matter is a hypothetical form of matter thought to account for approximately 85% of the matter in the universe. Dark matter is called "dark" because it does not appear to interact with the electromagnetic field, which means it does not ab ...

. The project is a collaboration between six international partners. It will be led by the

University of Melbourne The University of Melbourne is a public research university located in Melbourne, Australia. Founded in 1853, it is Australia's second oldest university and the oldest in Victoria. Its main campus is located in Parkville, an inner suburb nor ...

with the

Swinburne University of Technology Swinburne University of Technology (often simply called Swinburne) is a public research university based in Melbourne, Australia. It was founded in 1908 as the Eastern Suburbs Technical College by George Swinburne to serve those without access ...

, the

University of Adelaide The University of Adelaide (informally Adelaide University) is a public research university located in Adelaide, South Australia. Established in 1874, it is the third-oldest university in Australia. The university's main campus is located on N ...

, the

Australian National University The Australian National University (ANU) is a public research university located in Canberra, the capital of Australia. Its main campus in Acton encompasses seven teaching and research colleges, in addition to several national academies and ...

, the

Australian Nuclear Science and Technology Organisation The Australian Nuclear Science and Technology Organisation (ANSTO) is a statutory body of the Australian government, formed in 1987 to replace the Australian Atomic Energy Commission. Its head office and main facilities are in southern outs ...

(

ANSTO The Australian Nuclear Science and Technology Organisation (ANSTO) is a statutory body of the Australian government, formed in 1987 to replace the Australian Atomic Energy Commission. Its head office and main facilities are in southern outs ...

) and the Italian National Institute for Nuclear Physics. It is expected that the project will collaborate closely with the

Gran Sasso Laboratory Laboratori Nazionali del Gran Sasso (LNGS) is the largest underground research center in the world. Situated below Gran Sasso mountain in Italy, it is well known for particle physics research by the INFN. In addition to a surface portion of the ...

in Italy. Construction commenced in 2019, and though it was expected to be complete by the end of 2021 due to delays from corporate mergers it opened in August 2022.

General information

The project's Southern Hemisphere location has bearing on the possible differential detection of the putative

WIMP Wimp, WIMP, or Wimps may refer to: Science and technology * Weakly interacting massive particle, a hypothetical particle of dark matter * WIMP (computing), the "window, icon, menu, pointer" paradigm * WIMP (software bundle), the web stack of Wind ...

-wind. Northern Hemisphere instruments are showing hints of a June "bump" of possible dark matter hits, which is expected given the galaxy's rotation, but it is hard to be sure that it is not a false signal due to some subtle seasonal environmental effect. A Southern Hemisphere location, on the opposite side of the Earth with its converse seasons, could help to provide valuable confirmation one way or another. Secondly, the sundry particles (apparently from the constellation Cygnus) would have travelled through the Earth itself before reaching SUPL's instruments. Finally, its Southern Hemisphere location also makes it potentially very sensitive to daily variation effects which would be a smoking-gun for self-interacting dark matter or dark matter with a significant stopping rate. Inasmuch as

neutrino A neutrino ( ; denoted by the Greek letter ) is a fermion (an elementary particle with spin of ) that interacts only via the weak interaction and gravity. The neutrino is so named because it is electrically neutral and because its rest mass ...

experiments do not benefit in the same way from a Southern Hemisphere location, and

IceCube The IceCube Neutrino Observatory (or simply IceCube) is a neutrino observatory constructed at the Amundsen–Scott South Pole Station in Antarctica. The project is a recognized CERN experiment (RE10). Its thousands of sensors are located under t ...

is already extant, it is unlikely that any neutrino detectors will be housed at SUPL.

Funding

The first phase of the project received $1.75 million funding in the

2015 Australian federal budget The 2015 Australian federal budget was the federal budget to fund government services and operations for the 2015/16 financial year. The 2015 budget was the second and last submitted by the Abbott Government, since the Coalition's victory in t ...

. With matching funding from

, construction started 2016 and was expected to be complete in 2017. However, a series of corporate mergers in 2015 and 2016 disrupted plans. The project was stalled when the new owners dismissed most of the labour force and shut down the Stawell gold mine to a "care and maintenance" state in December 2016. In December 2017, yet another new owner announced their intention to reopen the mine and were supportive of the underground laboratory, allowing hope that construction would restart. In 2019, the project resumed. The 2019 Australian federal budget included $5 million for SUPL, and in July 2019 a memorandum of understanding between Stawell Gold Mines Pty Ltd, the Northern Grampians Shire Council, and the

was signed to build and operate the laboratory.

Construction

SUPL is planned to be located at a depth of , providing approximately 2900 metre water equivalent shielding against background

cosmic rays Cosmic rays are high-energy particles or clusters of particles (primarily represented by protons or atomic nuclei) that move through space at nearly the speed of light. They originate from the Sun, from outside of the Solar System in our own ...

. As a decline (ramp) mine, cars and trucks can be driven to the laboratory site. The laboratory will consist of a bespoke cavity of approximately 10 metres high and 10 metres wide () excavated into the rock from an existing part of the mine. The laboratory will be divided into of

clean room A cleanroom or clean room is an engineered space, which maintains a very low concentration of airborne particulates. It is well isolated, well-controlled from contamination, and actively cleansed. Such rooms are commonly needed for scientif ...

space for experiments, and of "dirty" loading area. A side tunnel 5 m wide and 20 m long () will house physical plant and personnel facilities.

SABRE

The first experiment planned for SUPL is SABRE Page 4 gives the latitude of the laboratory as 37°03′S = 37.05°S, but it is not clear if this is accurate for the laboratory proper, or is an approximation based on the latitude of the town of Stawell. (Sodium-iodide with Active Background REjection), based on 50 kg of thallium-doped sodium iodide. Two detectors will be built: one at LNGS and one at SUPL. Improving on the DAMA/LIBRA experiment, the SUPL detector implements additional features for background rejection: a 12 kL liquid scintillator veto, and a muon veto (experiment member, M. Mews, remains the expert on said muon veto). Consistent results between the two would be very strong evidence. As of August 2022, the SABRE experiment is expected to be constructed underground in SUPL during the last months of 2022, with data collection beginning in 2023.

References

External links

SUPL and SABRE
University of Adelaide
The Stawell Underground Physics Laboratory

ARC Centre of Excellence for Particle Physics
{{DEFAULTSORT:Stawell Underground Physics Laboratory Neutrino observatories Underground laboratories Research institutes in Australia Physics laboratories Physics beyond the Standard Model Laboratories in Australia 2015 establishments in Australia Stawell, Victoria