The Einstein Telescope is an advanced gravitational-wave observatory, currently in the planning stage.
The border region between the Netherlands, Belgium and Germany is being considered as a possible location. This is because of its tranquillity, stable ground and strong ecosystem of scientific institutions and high-tech companies.
An international panel will decide in 2024/2025 where the Einstein Telescope is to be built. It represents a huge opportunity for the region’s science, technology, businesses and economy. This is why scientists, companies and governments across the Meuse-Rhine Euroregion have joined forces to explore its candidacy.
There are two main reasons that make the Einstein Telescope much more accurate than existing gravitational wave detectors. First, the detector is placed 200-300 meters underground, far away from noise and other disturbances. The second reason is that the Einstein Telescope will feature new and innovative technologies. The E-TEST project (Einstein Telescope EMR Site & Technology) focuses on both aspects: the soil and technological innovation.
Previous studies have shown that the Euregio Meuse-Rhine (EMR) subsurface appears 'quiet enough' for the Einstein Telescope. But we need a better understanding of other factors and a wider area. That is why researchers are working on an underground monitoring system and a model of the subsurface. This will improve our knowledge about groundwater levels and sources that can interfere with planned detectors, such as seismic, atmospheric and anthropogenic noise. The research will also show where exactly the Einstein Telescope could be located. This requires an equilateral triangle with sides of 10 km at a depth of 200 to 300 meters. Important factors are the nature of the subsurface, the stability of the soil and the fluctuations of the groundwater. Scientists will also take into account the impact on the environment, because it should be as small as possible.
In the E-TEST project, partners from science and industry are also developing new technologies. They focus on optics, low-vibration cryogenics and seismic isolation. One of the main results of the project is a prototype silicon mirror for the Einstein Telescope. The cooled silicon mirrors are an innovation over existing gravitational wave detectors. They are less sensitive to noise and therefore improve the accuracy of the detector.
The project started in the spring of 2020 and will run until 2023. 11 partners from the Netherlands, Belgium and Germany are involved in the project, including KNMI. They work closely with business partners. The partners are: Fraunhofer-Institut für Lasertechnik ILT, Hasselt University, KU Leuven, Maastricht University, Nikhef, NMWP Management GmbH, Rheinische Friedrich-Wilhelms-Universität Bonn, Royal Netherlands Meteorological Institute (KNMI), RWTH Aachen, Université catholique de Louvain, and Université de Liège as lead partner. The project is co-financed by the Province of Limburg and the Ministry of Economic Affairs and Climate.
More information about the partners
Within the E-TEST project, KNMI's department R&D Seismology and Acoustics (R&DSA) will set up a seismic monitoring network in the region of interest. This network complements the already existing seismic instrumentation in the area. Acquired data will be used to image the subsurface and estimate the background noise levels at depth from surface and borehole measurements. The data collected by the permanent seismo-acoustic monitoring network and passive seismic campaigns are freely and openly distributed through the ORFEUS Data Center.
The E-TEST project is carried out under the Interreg VA Euregio Meuse-Rhine Programme, with 7.5 million Euro from the European Regional Development Fund (ERDF). By investing EU funds in Interreg projects, the European Union invests directly in economic development, innovation, territorial development, social inclusion and education in the Euregio Meuse-Rhine.