Andrew Harrison, an expert with a long track record in managing and organising research infrastructures, leads the working group that was installed by the Einstein Telescope Board of Governmental Representatives (BGR). The core of the Working Group on Site Selection Procedure and Criteria consists of twenty people, with eight additional members invited to contribute to specific sub groups. Andrew explains how the members of this work group were carefully chosen “Of course, it starts with finding people with the right expertise. On top of that, balanced representation of countries was a prerequisite. Those two things shaped the group’s composition. We also have four experts who provide additional expertise and who are not from a potential host country.”
The core work group meets monthly online, with an in-person meeting planned for September, and work is done in between these meetings. Additional experts are consulted or involved when necessary. The work itself is divided into four areas and sub groups: 1. Scientific and technical requirements of the detector, 2. Civil works, environment and geology, 3. Contextual factors: ecosystem, community and connectivity and 4. Overall costings and finance.
At this stage it has yet to be decided whether the Einstein Telescope will be a single site triangle-shaped observatory, or a multiple site double L-shaped observatory. Groundwork for geometry selection is currently being done by a group working on a Geometry Comparison Report, coordinated by the Einstein Telescope Organisation (ETO). The processes on site selection criteria and geometry comparison are run separately on purpose. They are however, inevitably linked and require similar input from and coordination with the same partners.
Andrew: “We are in touch with ETO to align on this. There are definitely parallels in the work we do, especially in costing. So we have to make sure we are not duplicating unnecessarily or in a divergent fashion. At the same time, we are both working at high speed to deliver a report in the autumn so it’s inevitable that some stakeholders are approached by both of us. Once those reports have been delivered, the different strands of work are expected to be brought together.”
There are currently three candidate sites for the Einstein Telescope: Sardinia, the Euregio Meuse-Rhine and Lusatia. The report on site selection procedure and criteria will not be an assessment of the candidate sites itself. It is instead meant to provide input and advice on how to make a decision. As Andrew explains “we are building on preparatory work and analysing existing information also used for site selection of other research infrastructures. From this, we identify what previous processes are most appropriate and apply some of them to ET. We will come up with a set of criteria and aim to propose how to weigh these criteria. But we will not do the assessment ourselves. We will formulate what we recommend to be included in the bidbooks of the candidate sites. It is important that the nature of data and evidence for information will be comparable across sites.”
It will be a busy rest of the summer and autumn for the members of this working group and those providing input. The report is due towards the end of 2026. After that, more preparation work towards a site selection will continue. All to support informed decision making on the road towards establishing this groundbreaking third-generation gravitational wave detector in Europe.
