Reflections on LINXS webinar series: Science at Large Scale Research Facilities

The LINXS webinar series, “Science at Large Scale Research Facilities”, is an excellent response to the coronavirus pandemic and provides the type of information one would get at a conference or at an actual facility. It’s also a good way to reach out to people who use x-rays and neutrons more seldomly and to grow the community, say Ken Andersen and Sakura Pascarelli. Read their reflections on research frontiers, the importance of knowledge sharing and the need to keep a long-time perspective.

Ken Andersen is Associate Laboratory Director for Neutron Sciences at Oak Ridge National Laboratory in the USA, and Sakura Pascarelli is Scientific Director at the European XFEL in Germany. Photo.

Both Ken Andersen, Associate Laboratory Director for Neutron Sciences at Oak Ridge National Laboratory in the USA, and Sakura Pascarelli, Scientific Director at the European XFEL in Germany, have presented their respective facility as part of LINXS webinar series: Science at Large Scale Research Facilities.

– My hope is that LINXS neutron-focused webinars might make x-rays users more interested in exploring neutrons. Rather than going to a neutron conference that might attract only hard-core users, you can catch people digitally who might use neutrons more seldomly or are only just beginning to the explore techniques available at places like Oak Ridge, says Ken Andersen.

Sakura Pascarelli agrees:

– Many young people have lost precious time in terms of doing real life experiments. Doing your PhD is a once in a life time opportunity that you do not recover. Giving digital talks like this is an attempt to show them a little of what you can do at the XFEL.

Many developments within x-rays and neutrons

While information sharing is important in any research field, recent trends in neutrons and x-rays have made initiatives like LINXS webinar series even more urgent emphasise Ken Andersen and Sakura Pascarelli.

Ken Andersen highlights how many smaller neutron facilities the world over have closed, for example in Germany and in France. These facilities would typically be suitable for less complex experiments – which are often the entry point for the more advanced neutron instruments offered at Oak Ridge, and in a few years’ time, at the ESS in Lund. The shutdowns are partly due to increased competition for funding, and partly due to unease amongst populations who live close to these types of research reactors.

– Of course, it is great for the community to have high-end, third-generation facilities like Oak Ridge and ESS. But they cannot replace the smaller facilities that are now shutting down. We need these to grow the user base and to provide more opportunities to conduct neutron research, says Ken Andersen.

– In the long-run, this is something we have to take more seriously. If you look worldwide, the group of people using neutrons is not growing. But in the meantime, creating arenas to get more people interested in neutrons, and to make information accessible for them, is a good start.

New possibilities within x-rays with XFEL

Meanwhile, the opportunities offered by the European XFEL have opened a swathe of new possibilities within the x-ray community. The XFEL beam generates ultrashort x-ray flashes, 27 000 times per second, and with a brilliance that is a billion times higher than that of the best conventional x-ray radiation sources. It can generate petabytes of data, and is suitable to observe and identify rare events, fluctuations and correlations. Yet, there are still many challenges connected to performing experiments with a beam this strong – and the coronavirus pandemic have further delayed progress on exploitation of the instruments.

– It takes ten years to mature a facility like the European XFEL. We need to have people coming, testing things out and asking questions. My wish is that, in a decade or so, we have figured out how to tear down some of the bricks in that wall that we are now hitting, especially in terms of preparing samples, and develop ways to harness the potential of all the data you can extract with the XFEL.

– The XFEL is very different to a regular synchrotron source and that’s why we need to educate researchers so they can use the beam. In a synchrotron, you have a pulse that is a hundred picoseconds long and during a hundred picosecond, molecules have time to vibrate. At XFEL, you have a x-ray pulse that is twenty femtoseconds, which means that the atoms do not move; they are photographed as ‘frozen’. Rather than getting an average result, you get a more detailed insight into your sample.

Energy materials is a key research frontier

Both Ken Andersen and Sakura Pascarelli emphasise that x-ray and neutron techniques have the potential to address some of our most pressing global challenges, including energy supply. As more sectors look to swap fossil fuels for renewables, by means of electrification, and our energy demand is set to increase by 25 percent by 2040, the need to find ways to harness, store and scale-up renewable energy sources is becoming even more pressing.

– If I had to pick one area where I really think neutrons can make a difference it is in energy materials. Neutron techniques can, for example, be used to make renewable hydrogen fuel cells more effective, by studying the catalysts and electrolytes in the cell, says Ken Andersen.

Sakura Pascarelli adds:

– Using sunlight and water to make hydrogen would be best in terms of sustainability. But today it is expensive, and we still have the problem of energy loss since the electronic charge generated by light absorption releases energy in the form of heat on the way to the site where it should do the splitting.

– My long-term ambition is that we will be able to solve some of these real-life problems with the help of experiments at facilities like the European XFEL. But you need to be patient. You will not see any immediate benefit right now; it will probably take ten or twenty years.

Basic science is key cornerstone

Finally, Sakura Pascarelli says that basic science, with no real-world application as of yet, also need to be prioritised in terms of funding and beamtime.

– We have to continue to do basic science. If people hadn’t been interested in solid state physics, say, fifty years ago, we would not have the Iphone with its touch-sensitive-screen or highly efficient rechargeable battery. It all starts with a basic understanding of materials: what they can do and how they behave on an atomic scale, she concludes.

Noomi Egan18 June 2021