Einstein Telescope

If it’s up to a consortium of Belgian, German and Dutch universities and research institutions, the coming years will be marked by intensive construction of the Einstein Telescope in Dutch Limburg, 200–300 metres beneath the earth’s crust. With this prestigious international project, scientists hope to monitor gravity waves, which will also be beneficial to the industry.

In the early 20^th century, Albert Einstein predicted the existence of gravity waves – fluctuations in the curvature of spacetime – in his theory of relativity. These gravity waves were observed for the first time in 2015. Two years later, this would result in a Nobel Prize in Physics for the three scientists involved. Since that time, gravity waves have been attracting considerable attention. This has even led to a new area of scientific research: gravitational-wave astronomy.

‘We use telescopes to monitor these gravity waves’, notes Nick van Remortel, a physics professor at the University of Antwerp. ‘In order to view stars, these telescopes should ideally be placed in the most remote locations possible. This is not the case for telescopes that are used to study gravity waves. We therefore need specific infrastructure, including high-tech lasers, with underground tunnels, which can be created even in densely populated areas. The underground character is important in order to suppress natural vibrations, as well as those caused by human activity’.

The ET Pathfinder is coming

A Belgian-German-Dutch consortium has concrete plans to realise the Einstein Telescope (ET) in the ground of Dutch Limburg. This project would be conducted within the framework of the new ESFRI Roadmap (European Strategy Forum on Research Infrastructures). If the consortium is successful – another location is also in competition – construction on the 15-kilometre long tunnels could start around 2025, so that the ET could go live in 2032. Europe will reach its final decision in 2021.

On Thursday 18 July, the preliminary plans were presented in the Port House in Antwerp. ‘Although we are obviously very eager to realise the Einstein Telescope, which will be a showcase for the new generation of large-scale research infrastructure’, explains Remortel, ‘the telescope will not be an entity unto itself. In the time leading up to our candidacy, the partners would like to build a hyper-modern research facility – the “ET Pathfinder”, in Maastricht. This infrastructure is expected to grow into an international centre for research on gravitational-wave astronomy, high-precision measurement techniques, seismic isolation, measuring-and-control software, cryogenic technology and optics (including quantum optics)’.

Expertise from the industry

Although the ET Pathfinder will be crucial for the scientists of the consortium, international researchers will also be finding their way to Maastricht. The project will be financed with funds from the European INTERREG programme, supplemented by start-up capital from the Dutch and Flemish governments, as well as from the provinces and universities involved.

Van Remortel continues, ‘Most of the research to be conducted will be fundamental, but on an industrial scale. We scientists set extremely high quality requirements for the instruments that we need. Expertise from the industry is therefore necessary. This will bring science and technology into cross-pollination with the industry. Examples that come to mind include such new technologies as refrigerated silicon mirrors. The entire project will have to be housed in a “cleanroom”, an extremely dust-free environment. This will also call for expertise from the industry’.