Recent articles in the French newspapers Le Monde and Le Point highlight the importance of neutrons as a probe of matter, materials and processes for science and innovation for the research community and for industry in France, and indeed Europe.
The article describes the French contribution to the European Spallation Source (ESS), which is under construction in Sweden, and the need for a new national source, ICONE. The availability of neutrons in France is in a critical situation since the previous French national source, Orphée at LLB, has been closed and the current European source, ILL, in Grenoble is planned to end operation in 2030 or 2033, according to the current agreement between France, Germany and the UK.
Since the ILL has the brightest neutron beams and the largest instrument suite (fully modernised from 2016 to 2023) in the world, the message behind the article is that there is a risk of a capacity and capability gap if existing sources end operation before new sources are brought online. Indeed, the success of the new sources will depend critically on the vibrant research community supported by the existing sources, in particular the ILL.
In this context, it is crucial to understand the timescales involved – from the examples of ILL, ISIS in the UK and SNS in the US, a new large scale facility takes a decade, following the start of the user programme, to reach nominal, initial performance. For the ESS, this means that it will reach technical and scientific maturity in the mid-2030s, at which stage it will likely have less than half the capacity of the ILL.
World-class research needs new sources and facilities but the transition towards these must be carefully managed. The time frame for this transition stretches well into the 2040s.