Professor Andrew Harrison: Bringing neutrons to the masses

Neutrons can be used to answer questions in most scientific disciplines says Professor Andrew Harrison, Director of the Institut Laue-Langevin. Here he tells us all about this amazing resource

 What is the Institut Laue-Langevin? Describe its mission

The Institut Laue-Langevin is an international research centre at the leading edge of neutron science and based in Grenoble, France.

As the world’s flagship centre for neutron science, our aim is to provide scientists from our member countries with a very high flux of neutrons. These feed some 40 state-of-the-art instruments, which are constantly being developed and upgraded to help them probe matter of all types and look at its structure and composition.

We are really a resource for the international science community, offering them both state of the art equipment, and access to thousands of scientists who combine a specialism in areas as diverse as chemistry, physics, biology and engineering, with a deep understanding of how neutrons can be used to answer questions in these disciplines.

What was your scientific background before you were appointed director of the ILL? Did you welcome the move to Grenoble?

 I am actually a chemist originally and studied at Oxford University before becoming a Royal Society University Research Fellow. I then joined Edinburgh University in 1992, where I still hold a position as a Professor of Solid-State Chemistry.

At Edinburgh I helped found the Centre for Science at Extreme Conditions which as part of its mission aimed to provide access for UK researchers to state-of-the-art techniques and expertise at the limits of temperature, pressure and magnetic fields, including synchrotron and neutron techniques.

Prior to joining as Scientific Director of the ILL in 2006, I spent a lot of time as a pure researcher at neutron sources around the world, including ILL, studying the magnetic properties of materials, and saw for myself the diversity of expertise at Institutes like ILL and how it creates a very fertile environment for research and pursing new ideas. It made the opportunity to take on a full time position at the ILL one that I couldn’t pass up.

Describe a typical day for you at the ILL. Is it an exciting place to work?

It’s a real mixture of activities, all tied in to making sure we continue to serve our community of scientists in the best way we can. Activities could involve discussing plans for the next generation of instruments or overseeing upgrades of existing ones to keep us at the forefront of neutron science, where we have been for over 40 years.

I am also in regular contact with funders from our 10 member countries to ensure they are happy with the service we provide and I’m frequently talking to potential new member countries to encourage them to partner with us.

I am also currently chair of the Eiroforum, a partnership between eight of Europe's leading inter-governmental scientific research organisations of which ILL represents neutron science. In this role I look for areas for future collaboration and resource sharing as well as providing European science with a voice at the highest levels of European policy.

There is certainly a lot involved in running an international class institute like ILL but when you have some of the world’s best scientists and engineers all mixing together it makes for a very exciting place to work. Also sitting up here at the base of the Alps in the beautiful city of Grenoble means the views out of the window aren’t too bad either.

What sorts of experiments are carried out there? Could you give us some examples of current projects at the facility?

As a probe of matter the neutrons at ILL are exploited in a variety of ways to investigate materials over many scales of distance and time, across various research fields’.

At the ILL we have scientists making ground breaking discoveries in areas as varied as healthcare, the environment and engineering, as well as improving our fundamental knowledge of how the world works.

In biology, the ILL houses world leading facilities to explore a very wide range of systems, from cell membranes to the structure and dynamics of proteins. Our neutrons provide important insights into new therapies such as the action of potential drugs on viruses and the cell walls through which they are delivered. To take a recent example, last year our neutrons helped explain why antibiotics prescribed to chemotherapy patients all over the world can cause kidney failure and other life-threatening complications.

Surfactants are another area of research at ILL and last year scientists from Bristol University published a paper describing neutron investigation of the world’s first magnetic soap. Their analyses demonstrated how iron, added to an existing soap, can maintain its magnetic properties under the right conditions, creating a potential highly valuable product in applications such as environmental clean-up operations.

ILL also works with engineering firms using neutrons to identify potential structural vulnerabilities within components such as railway tracks and turbine blades for jet engines. Whilst for more fundamental physics we produce neutrons of extremely low energy, called ultra-cold neutrons whose properties are being measured extremely precisely in order to look for signs of a new science beyond the Standard Model of physics.

How are neutrons produced and what types of neutrons are used for the various experiments?

The source of our neutrons is our high-flux reactor that operates continuously for 50-day cycles. Normally there are four cycles a year, providing up to 200 days for science.  Our reactor produces the most intense continuous neutron flux in the world in the moderator region with 1.5x10¹⁵neutrons produced per second per cm² with a thermal power of 58.3 MW.

The high-flux research reactor produces these neutrons through fission in a specially designed, compact-core fuel element. Neutron moderators cool the neutrons to useful energies or wavelengths, which are then directed at a suite of instruments and used to probe the structure and behaviour of many forms of matter.

At ILL we produce our neutrons over a wide range of energies from hot ones (with an energy of about 0.2 eV that whizz around at a couple of kilometres per second) to ultra-cold ones (with energies less than 3 × 10^?7 eV, which move slower than most people can run).This variety of energies correspond to wavelengths that vary from 0.1 angstrom (one ten-billionth of a metre) to 10,000 times that. This means neutrons can be used to study structures at both the atomic and macromolecular scale.

What are the advantages of using neutrons in different fields of research (over X-rays, for example)?

Neutrons have various properties similar to x-rays that can tell us about the structure of materials down to the atomic scale, but there are others that completely unique to them. For example, neutrons behave as small magnets, making them an ideal probe for understanding the structure and dynamics of magnetic matter.

Their ability to distinguish elements at the lighter end of the periodic table – for example hydrogen and oxygen -  also contrast to x-rays, which are scattered much more strongly by heavy atoms. It is this contrast which helps make neutrons and x-ray such a complementary pair of techniques.

As well as different light elements, neutrons can also discriminate between different isotopes of the same element. In neutron science this is used in a process called deuteration, whereby deuterium, the heavier isotope of hydrogen, is introduced and contrasted with undeuterated samples to pick out the location of hydrogen atoms. It’s a technique which is used heavily in the analysis of surfactant molecules such as in research informing future soap development, and also drug delivery research in biology, tracking how compounds breakthrough our cell membranes in real time.

At ILL we have the world’s bright neutron source right next door to the world leading, x-ray producing European Synchrotron Radiation facility. It is a unique set up which has allowed the two facilities to set up joint projects and labs that have helped attract many of the world’s leading scientists to Grenoble.

How would a scientist that wanted to use ILL facilities for their research go about applying for beam time? What’s the selection process like?

The most common way to submit a proposal is through our website (www.ill.eu). However there are several alternative options for potential users depending on their exact requirement. These are described in more detail –at: http://www.ill.eu/users/applying-for-beamtime/  Scientists who have not used neutron scattering before can get technical advice about how best to exploit the technique by contacting one of our in-house scientific experts, again outlined on our web site.  The selection process is run by a committee of experts who assess proposals based above all on the quality of the science.