Neutrons

Neutrons play a definitive role in understanding the material world. They can show where atoms are and what atoms do.

By scattering neutrons off materials, scientists can visualise the positions and motions of atoms and make discoveries that have the potential to affect almost every aspect of our lives. Results from neutron experiments can help us to develop new materials for every-day uses.

Neutrons are used to study the dynamics of chemical reactions at interfaces for chemical and biochemical engineering, food sciences, drug synthesis and molecular biology.

Neutrons can probe deep into solid objects such as turbine blades, gas pipelines and welds to give a unique microscopic insight into the strains and stresses that affect the operational lifetimes of these crucial engineering components.

Neutron studies of nano-particles, low-dimensional systems and magnetism impact upon next generation computer and IT technology, data storage, sensors and superconducting materials.

Neutrons can be used for studying geological samples, new materials for energy production and storage, chemicals which affect the environment, and polymers and plastics. They can be used to study materials for health – from new materials for hip implants to gels that can help babies with clef palates. They have a very wide variety of uses!

Almost all of the major changes in our society, the dramatic revolutions in transport and manufacturing, the growth of computing and the internet and the steady increase in average life span, have their origin in understanding and exploiting the physics and chemistry of materials.

The goal of modern materials science is to understand the properties of matter on the atomic scale, and to use this knowledge to optimise the properties or develop new materials.

In neutron scattering experiments, materials are exposed to intense beams of neutrons inside specialised instruments at large research centres. The images that are made are used to reveal the molecular structure inside the material which can be directly linked to the physical and chemical properties experienced in the everyday world.

The UK is home to Europe's largest neutron scattering community and operates a world-leading short-pulse spallation source, ISIS at the STFC Rutherford Appleton Laboratory (RAL) and manages the UK subscription to the world-leading reactor source, Institut Laue-Langevin (ILL) in Grenoble. We have invested heavily in these facilities for the UK neutron scattering community through the development of a second target station at ISIS and through our support for the ILL Millennium Programme at ILL. The UK is also making a significant contribution to the construction of the European Spallation Source (ESS) currently being built in Lund, Sweden.

From this knowledge emerges fascinating new science or an understanding of current problems in industry.

STFC ensures that research using neutron scattering continues to make a valuable contribution to society through its on-going funding and development of the ISIS Neutron and Muon Source in the UK and the Institut Laue-Langevin in France.

We see a new, multi-MW long-pulse spallation source as a potential successor to ILL which would maintain and enhance the capacity and capability available to the UK community. At our recent town meeting of the UK neutron community, strong interest and support was expressed for the European Spallation Source, but it was also clear that the community also wishes to see the continued operation and upgrades of the two major existing facilities ISIS and ILL. We have taken these messages on board.

We believe that a coherent approach to the provision of neutron sources in Europe is vital. This strategy needs to address continued operation and upgrades to ILL and ISIS, as well as the role of a new European Spallation Source (ESS). We believe that any major new investments in neutron facilities in Europe should be considered within the overall European landscape in neutron scattering; we should make sure we have a balanced programme that meets the science needs of the European research area. The UK wishes to have a leading role in the development of this strategy.

To these ends, the UK attended an informal meeting to exchange information concerning the interest of participation of EU Member States in ESS which took place on the 27th November 2008 in the German Permanent Representation in Brussels. The aim of this meeting was to further support the ongoing process of setting up ESS as a European Research Infrastructure. It was agreed that:

  • There is a broad interest in Europe to build a next generation neutron source (the European Spallation Source) and there are three very qualified bids to host the ESS.
     
  • A decision by Ministers on the site for ESS could be taken within 6 months. It was agreed that only after the selection of the site could the design review of the project start or formal commitments of Member States be possible.
     
  • The need to have a strategy to coordinate existing and future Neutron Facilities in Europe was agreed.

We intend to participate fully in this process as it continues to develop.

Key facts

Neutrons have unique advantages as a probe of atomic-level properties:

  • The process of neutron scattering is non-destructive, so that delicate or valuable samples can be studied
  • Neutrons are penetrating, so that they can look deep inside engineering samples to study, for example, welds
  • Neutrons with energies in the range of atomic motions have wavelengths of the order of the distances between atoms – making them very good at studying both where atoms are and how they are moving
  • Neutrons are good at seeing light atoms, such as hydrogen, in the presence of heavier ones
  • Neutrons are good at distinguishing neighbouring elements in the periodic table
  • Different isotopes of the same element scatter neutrons differently. For example, extra information can be gained by swapping hydrogen atoms with their deuterium isotopes in part of a sample
  • Neutrons have a magnetic moment, meaning that they can be used to study the magnetic properties of materials

Neutrons provide complementary information to other techniques such as x-ray scattering, so many researchers use neutron facilities such as ISIS and ILL alongside x-ray sources such as Diamond or the ESRF.

STFC manages access for UK scientists and researchers to both facilities. It wholly owns ISIS and has a one third stake in the ILL facility, with the remaining two thirds being owned by France and Germany and additional support being provided from 10 other European member countries.

The unique qualities of neutrons allow researchers to:

  • determine the structure of solids and liquids at an atomic or molecular scale
     
  • work on engine design, fuels, plastics, electronic devices and household products
     
  • reveal the forces and processes fundamental to materials, chemical processes and life
     
  • provide incisive information on a material’s magnetic properties
     
  • undertake non-destructive analysis of delicate biological or polymer samples in clinical trials

Previous and ongoing projects include:

  • enhancing materials for hydrogen storage to provide practical, new and renewable energy technology
     
  • understanding the properties of biomolecules essential to better health and healthcare
     
  • revealing the link between high-temperature superconductors and their magnetism, leading to improved materials with applications ranging from MRI to faster computing devices
     
  • examining materials at extremely high temperature and pressure for new processing technology as well as studying the geophysical principles governing the structure of our planet
     
  • pushing recording densities in magnetic media to quantum limits, laying the foundation for a revolution in information technology
     
  • testing the feasibility of different nuclear fuel cycles including nuclear power with lower-activity waste
     
  • understanding and controlling the way polymers behave as they are processed to improve plastics and fibres

Science

Neutrons are neutral sub-atomic particles with no electrical charge. Because of this, these unassuming particles are non-destructive and can penetrate into matter much deeper than charged particles such as electrons. In addition, because they have a property called spin, neutrons can be used to probe magnetism on an atomic scale.

There are two main methods of producing neutrons for materials research. One is by splitting uranium atoms in a nuclear fission reactor. The other, called spallation, involves firing high-energy protons into a metal target, such as mercury or tungsten, to induce a nuclear reaction that produces neutron beams.

ILL is the most intense reactor neutron source in the world. ISIS is the most productive spallation neutron source in the world.

Neutron sources play a crucial role in research across the scientific spectrum, from nuclear and elementary particle physics, chemistry and materials science to engineering and life sciences.

Neutron techniques complement synchrotron X-ray techniques for studying materials. Through ILL and ISIS, and the synchrotron facilities ESRF and Diamond, STFC is helping to keep the UK at the forefront of ground-breaking research worldwide.

Resources

Links

Neutron scattering can be performed at neutron sources such as ISIS in the UK and the ILL in Grenoble, France – please see these websites for more detailed information and how to get time at one of these neutron facilities.

Contacts

Jennifer Scratcher
Programme Manager, Light Sources and Neutrons Division
Tel: +44 (0)1793 418 038
ILL website
ISIS website

For media enquiries please telephone: +44 (0)1235 445 627

Case studies

Neutrons and Energy

Neutrons are helping to address the World’s ever-changing energy needs. From designing hydrogen-rich storage materials to investigating the most efficient solar cells, neutron scattering experiments are helping us develop long term sustainable energy solutions. As well as looking at future energy sources, neutron experiments are enabling extended life-spans for current nuclear power plants, reducing the requirements for expensive decommissioning.

Neutrons and the Environment

Neutrons are being used to tackle environmental challenges – trying to find ways to make sure that the environment around us remains stable and unspoilt. Research at ISIS has been used to study the way that air pollution changes cloud formation and to investigate the environmental management of common nanoparticles.

Neutrons and Health

Scientists are using neutrons to combat public health issues that are becoming more apparent due to our aging population. Research at ILL has demonstrated that the movement of cholesterol between cells is much slower than previously thought, information which may affect treatment options for disorders such as Alzheimer’s disease, while the life-span of artificial limbs may be improved through analysis of the joint coatings using neutrons. Young children are also feeling the effect, with those being born with cleft pallet now having new treatment options thanks to neutron scattering experiments on a revolutionary hydrogel.

Neutrons and the Natural World

Neutron scattering at ISIS and ILL is being used to develop our understanding of the Earth’s geology and natural environment. New insights into the properties of spider silk or the molecular mechanism of defence proteins in crops are helping scientists harness these natural properties for wider uses. Meanwhile, geologists are using neutron scattering to help model the interior the Earth and predict the geology of planetary moons.

Neutrons and Electronics

Neutron experiments are helping scientists to develop electronic systems to make them more efficient and productive for the future. Leading aerospace engineering companies are using the ISIS neutron facility to test electronic components, replicating hundreds of years of flying in an hour of testing, to manage the effects of cosmic radiation on devices. Electronics on a much smaller scale are also being changed, with ceramic components inside mobile phones being investigated using neutrons to help the manufacturing company achieve exactly the right specification.

Neutrons and Industry

The molecular-level views obtained using neutrons of the structures of certain chemicals have enabled scientists to see exactly what happens on the surface of catalysts used in industrial processes, and improve these for the future. Organic solvents used in the chemical industry can be hazardous to use, but neutron studies are helping to develop new solvents which are non-flammable and which don’t affect the final product.

Neutrons and Heritage Studies

Neutron scattering is a non-destructive way to look at ancient artefacts and fossils without having to break into them or damage them in any way. Across Europe neutron sources are delving deep into historic relics, from Japanese swords from the 14th Century, to the battlefield weapons of the War of the Roses. These experiments are shedding new light on historic events in a way that has never been done before.

History

Nobel Laureate Louis Néel was one of ILL’s founding fathers in 1967. His work on magnetism underpins, for example, the magnetic recording technology used in modern computers.

Experiments at ILL proved the theoretical work of another Nobel Laureate, Pierre-Gilles de Gennes; this basic physics research was crucial for improving the industrial production of many plastics and fibres.

Nobel Laureate Norman Ramsey’s work helped develop the technology behind the STFC-Sussex CryoEDM experiment at ILL. This will test some of most fundamental theories of our universe such as the Standard Model of particle physics and the reasons for an imbalance between matter and antimatter.

Nobel Laureate Sir Harry Kroto used ISIS in 1991 to determine the crystal structure and bonding of C60 carbon ‘buckyballs’. His early research into this new form of carbon has since produced an entirely new field of chemistry and industrial applications.

Science and Technology Facilities Council Switchboard: 01793 442000