ESS Competence Centre
In 2014, the foundation stone was laid for the European Spallation Source (ESS) in Lund, Sweden. The joint project involving 17 European countries is due to go into operation with its first instruments in 2019. Full operation with 22 instruments is planned for 2025. ESS will generate the world’s most powerful neutron pulses and provide unique insights into matter for basic research and application-oriented research.
The ESS Competence Centre, which was founded in 2011 at Forschungszentrum Jülich, coordinates the contributions made by the Jülich Centre for Neutron Science (JCNS) and the Central Institute of Engineering, Electronics and Analytics (ZEA) to the planning and construction of ESS and its instruments. Within the Competence Centre, scientists, engineers, and technicians develop concepts for central components of ESS: for the target, where the neutrons are released, as well as for scientific instruments and detectors. The work at Jülich is rooted in years of experience in constructing, operating, and utilizing neutron scattering instruments dating back to 1962.
ESS The European Spallation Source (ESS) in Lund, Sweden, will be some 650 metres long including 500 metres underground. More than 50,000 cubic metres of concrete, 40 kilometres of pipelines, and 2,000 kilometres of cables will be required for the construction.
The high power produced by ESS is particularly challenging with respect to the target and was an important design parameter for the experts at ZEA’s subinstitute Engineering and Technology (ZEA-1). The target in a spallation facility is the area where proton salvoes impact thus releasing neutron pulses. As ESS is a high-power source, a great deal of thermal energy is generated during this process and must be continuously removed.
In the Design Update Phase from 2010 to 2014, ZEA worked on revising the design of a cooled, rotating target wheel made of tungsten. For the sophisticated design, Jülich’s developers drew on Jülich’s own experience gained in past design studies and also took account of lessons learned at other high-power spallation sources in Japan and the USA. In addition, they ran simulation calculations and tests on prototypes.
ESS will generate more powerful and longer pulses than the spallation sources in Japan and the USA. Its frequency of 14 hertz is lower than in the USA (60 hertz). As a result of the high intensity of the pulses, many more neutrons can be utilized for science at the instruments than at conventional sources. This opens up new possibilities for researchers, but the instruments must be adapted to the special conditions at ESS. As a result, the project team are designing, developing, and constructing customized scientific instruments especially for the new source.
At Jülich, for example, research scientists are working on a time-of-flight spectrometer, which can exploit the pulse structure of ESS particularly well. This instrument will allow new insights into the structure and dynamics of complex materials, for example, into magnetic excitations in high-temperature superconductors.
To enable optimum use of the neutron pulses at ESS in highly advanced instruments, innovative detectors are needed. They elicit information from the neutrons about the structure, movement, and, in some cases, magnetic properties of the material samples studied. Areas of many square metres mean that the site and point in time of the neutron impact must be precisely measured. This is a huge challenge, especially because tried and tested designs work with the rare and expensive gas helium-3. As this is becoming even more expensive, new detector designs are essential and this is what the experts at ZEA-2 (Electronic Systems) are working on. In addition, they are looking at concepts for control electronics.
In the Design Update Phase (2010–2014), the German Federal Ministry of Education and Research (BMBF) provided funding worth some € 6 million for the activities at Jülich. Another € 9 million went to the other German research institutions involved. Now, the Jülich project team is preparing for the Construction Phase.
Dr. Andreas Wischnewski
Head of the ESS Competence Centre
Tel: +49 2461 61-4749
Fax: +49 2461 61-2610
How Spallation Works
European Spallation Source (ESS)
History of Neutron Research in Jülich
Central Institute for Engineering, Electronics and Analytics (ZEA)
Division for ESS Instrumentation (JCNS / ICS)