European Spallation Source

The European Spallation Source ERIC (ESS) is a multi-disciplinary research facility currently under construction in Lund, Sweden. Its Data Management and Software Centre (DMSC) is co-located with DTU in Lyngby, Denmark. Its 13 European contributor countries (Czech Republic, Denmark, Estonia, France, Germany, Hungary, Italy, Norway, Poland, Spain, Sweden, Switzerland and the United Kingdom) are partners in the construction and operation of the ESS. The ESS is scheduled to begin its scientific user program in 2027, when the construction phase is set to be completed. The ESS will assist scientists from the partner countries in the tasks of determining and understanding basic atomic and magnetic structures and the associated dynamic atomic and magnetic properties, which are more challenging to probe with other neutron sources in terms of lengths and time scales. The research facility is located near the MAX IV Laboratory, which conducts complementary synchrotron radiation research. The construction of the ESS facility began in the summer of 2014 and the first science results are planned for 2027.

During operation, the ESS will use nuclear spallation, a process in which neutrons are liberated from heavy elements by high energy protons. This is considered to be a safer process than uranium fission since the reaction requires an external energy supply which can be stopped easily. Furthermore, spallation produces more usable neutrons for a given amount of waste heat than fission. The ESS facility is an example of a "long-pulse" source (milliseconds).. By contrast, other large-scale spallation sources ISIS, SNS, China Spallation Neutron Source and J-PARC are examples of "short-pulse" sources. The unique long-pulse nature of the ESS, in combination with the very large peak brilliance of the resulting neutron beam is expected to facilitate experiments that have not been possible at existing sources, e.g. because the signals of interest are too weak, the available sample sizes are too small, or the time-scales of interest are too short.

The ESS facility consists of a linear accelerator, in which protons are accelerated to relativistic speeds and then allowed to collide with a rotating, helium-cooled tungsten target wheel, generating intense pulses of neutrons. Located above the tungsten wheel are baths of cryogenic hydrogen and water at room temperature. High-energy neutrons released from tungsten nuclei in the spallation process lose most of their energy by inelastic collisions inside the hydrogen and water moderators and come into thermal equilibrium at the temperatures of these media. The cold and thermal neutrons emanating from the surface of the moderators feed neutron supermirror guides. The guides operate similarly to optical fibres, directing the beams of neutrons to experimental stations, where research is performed on a range of materials.

Neutron scattering can be applied to a range of scientific explorations in physics, chemistry, geology, biology, and medicine. Neutrons serve as a probe for revealing the structure and function of matter from the microscopic down to the atomic scale, with the potential for development of new materials and processes.

During construction, the ESS became a European Research Infrastructure Consortium, or ERIC, on 1 October 2015.

The European Investment Bank made a €50 million investment in the ESS. This investment is supported by InnovFin-EU Finance for Innovators, an initiative established by the EIB Group in collaboration with the European Commission under Horizon 2020, the EU's research and innovation program.