International agreement signed for fusion materials research facility

The Multilateral International DONES Agreement (MIDA) was signed at Spain's Ministry of Science, Innovation and University, in Madrid, by Marc Lachaise, Director of Fusion for Energy (F4E); Ángel Ibarra, Director of IFMIF-DONES Spain; David Smith, Director of the Croatia's Ruđer Bošković Institute; Koyasu Shigeo, President of Japan's National Institutes for Quantum Science and Technology; and Diego Bettoni, Vice President of Italy's Istituto Nazionale di Fisica Nucleare.

The MIDA gives a legal framework to the international collaboration that drives the DONES Programme. It sets the governance, the in-kind and financial contributions, management principles and tools, as well as provisions like the intellectual property policy.

Building and commissioning IFMIF-DONES will mobilise investments from the parties.  Through F4E, the EU will provide 25% of the construction costs, an investment of EUR202 million (USD233 million). The European contribution will include advanced technologies like the particle accelerator (building on the LIPAc prototype). Spain will be the main contributor, with 55% of the costs. Italy (8%), Japan (5.1%) and Croatia (5%) also committed their shares.

The MIDA signing event was followed by the meeting of the DONES Steering Committee, with representatives from 17 countries, along with delegates from the European Commission, F4E and EUROfusion. The delegates heard about the progress of the programme in aspects like safety, design and procurement arrangements.

The level of neutron irradiation planned for demonstration fusion power plants (DEMOs) has never been tested. In order to build DEMOs out of materials that can withstand such harsh bombardment, developers are looking to neutron sources as a way to mimic fusion conditions for materials testing.

The IFMIF-DONES (which stands for International Fusion Materials Irradiation Facility - DEMO-Oriented Neutron Source) materials testing facility will simulate demonstration fusion power plant-like conditions for potential structural materials. It will use a particle accelerator to produce a continuous-wave deuteron (D+) beam aimed at a target made of a liquid lithium curtain. The interaction between deuterium and lithium will generate enough free neutrons to simulate the planned neutron flux over time of Europe's DEMO, which is being designed by the DEMO Central Team at EUROfusion. Directly behind the lithium target will be the high-flux test module, which will house capsules of material samples for neutron irradiance testing.

The facility will produce a 125 mA deuteron beam, accelerated up to 40 MeV and shaped to have a nominal cross section in the range from 100 mm x 50 mm to 200 mm x 50 mm, impinging on a liquid lithium target 25 mm thick cross‐flowing at about 15 m/s in front of it.

The mission of the programme is to develop a database of fusion‐like neutron irradiation effects in the materials required for the construction of demonstration fusion power plants for benchmarking of radiation response of materials.

The IFMIF-DONES particle accelerator will generate unique experimental data that will also benefit other areas of science and technology, including medicine, nuclear physics, and various industrial applications.

The project is being implemented by the IFMIF-DONES Spain Consortium, established in 2021 through an agreement between the Government of Spain and the Regional Government of Andalusia, and attached to Spain's General State Administration.