Sweden to host a new neutron source

The first European neutron source, currently under development, should commence operations by the end of this decade. Its aim: to produce beams of neutrons that can penetrate into the heart of matter without damaging it and reveal its secrets.


An artist's impression of what the ESS should look like in 2019.

At the southern end of Sweden, a town called Lund is preparing for the arrival of the world's most powerful neutron source: the European Spallation Source (ESS). Construction is scheduled to start at the beginning of next year, and the facility is expected to become operational by 2019, when it will produce its first neutron beams.

“The ESS is the result of an idea that began 20 years ago!” underlines Mats Lindroos, in charge of the ESS Accelerator Division. “Today, 17 European countries support the project, including Sweden, Denmark and Norway, who together account for 50% of the construction funding.”

The ESS, whose design is also the result of international cooperation, benefits from the expertise and skills of major European research centres. “CERN is participating in the development of the entire accelerator part,” explains Christine Darve, the engineer responsible for the cryomodule portion. “For the ESS target, which will be made of tungsten, we are cooperating above all with nuclear physics experts.”

The ESS will operate at a power of 5 MW and may reach even higher powers in the future.  “There are several spallation neutron sources in the world, including pulsed sources such as SNS in Oak Ridge, USA, with its negatively charged hydrogen ion beams operating at up to 1.4 MW, and the MLF at J-PARC in Japan, with its proton beams that can operate up to 1 MW, although it is currently recovering from the devastating tsunami which damaged some of its infrastructure,” explains Christine Darve. “ISIS in the UK also allows for measurements to be taken, but at lower power. The Paul Scherrer Institute (PSI) in Switzerland also operates a very powerful continuous spallation source of 1.4 MW called SINQ. The ESS will be based on a novel source concept that uses a ‘long’, but not continuous, proton pulse at very high beam power, thus encompassing many of benefits of the two concepts.”

With their neutral charge, neutrons are an ideal tool for probing into the heart of matter and understanding its structure without changing it. “There is a wide field of application,” observes Christine Darve. “The possibilities offered by ESS are numerous and include medicine, the analysis of certain proteins, nanotechnology, the development of new materials, and archaeology, to understand how different objects are created.”(Visit the Laue-Langevin Institute and Société française de neutronique websites for more information).

22 types of neutron beams, depending on the specific needs of the experiments, will be at the disposal of 6,000 potential users. As with ISOLDE and the other beam lines at CERN, beam time will be leased. “Cold neutron beams (with long wavelengths) and thermal neutron beams (with short and medium wavelengths) will be available to users,” says Christine Darve. “These users will be from both academic and industrial fields.”

A further advantage is that another advanced facility is currently under construction on the same site as the ESS: MAX IV, a high-luminosity synchrotron radiation source financed by Sweden. That should please the most demanding customers, giving them the possibility of submitting their materials to very advanced and complementary studies within a radius of just a few kilometres.

ESS is now hiring! For more information, click here.

by Anaïs Schaeffer