7. May 2013

The idea-collector

SwissFEL SwissFEL Experiments Large Research Facilities

An interview with Bruce Patterson

Personal details:
Bruce Patterson (64) studied physics at the University of Chicago and got his degree at Berkeley. In 1975 he came to the University of Zurich, where he has been a titular professor since 1995. He has been employed at PSI since 1988, recently as Materials Science Beamline Scientist at the Swiss Light Source. Since 2007, he is the Scientific Coordinator of the X-ray free-electron laser project SwissFEL, and he will continue to work part-time for the project after his upcoming retirement. In his free time, he sings American love songs in a “Barbershop Quartet”, or he designs three-dimensional symmetric puzzles.
Mr. Patterson, your job is to identify which experiments the future SwissFEL users wish to perform and, by consulting with the machine experts, to determine whether they are technically feasible. I imagine that this is not an easy task.

I have the best job at PSI. I get to juggle fascinating theoretical concepts and experimental ideas, with the support of the project management. And when something is not clear, there is almost always someone at the institute who knows the answer. PSI has a critical mass of highly qualified and motivated personnel.

What is special about SwissFEL?

The 10 year old Swiss Light Source (SLS) synchrotron is a big success story at PSI. The X-ray intensity of the SwissFEL will exceed that of the SLS by the same factor as that of the SLS compared to the first apparatus of Wilhelm Conrad Röntgen, from 1899 – an incredible jump in experimental possibilities. The SwissFEL will be a precision Swiss watch, and the exact, ultrashort, blindingly bright X-ray pulses which it will generate will allow us to follow chemical reactions and magnetic interactions at the nanometer and femtosecond length and time scales.

What is the source for ideas for SwissFEL applications?

It is challenging to predict into which areas of science the SwissFEL will carry us. I spend a lot of my time on the internet, and I travel alot for discussions with scientific colleagues. I’m also good at stealing ideas. I try to identify the people with the best ideas, and then I invite them to PSI to present them to my co-workers. Up to now, scientists from at least 27 institutions have lent us their inspiration – 9 of these are in Switzerland.

You like to refer to the SwissFEL as an idea-generator.

A walk around the SLS, to see which experiments are presently running, is like reading a recent issue of “Scientific American”. With the SwissFEL, the possibilities grow still further. If one can collect enough talented people at a single facility, the ideas bloom. A project like the SwissFEL, at the border of what is technically possible, is particularly effective in inspiring new ideas. It’s like being at the tree-line in the mountains – where different ecosystems meet. A biologist friend explained to me how such regions of high ecological gradients generate new plant and animal species. An example is the Nutcracker, a bird which collects seeds in the forest and hides them in the tundra.

It is rumored that there is a direct connection between SwissFEL ideas and coffee.

I have organized weekly “Machine-Science Coffee” meetings, to promote the flow of ideas between the people planning the SwissFEL machine and those planning its future use. The corresponding project heads, Hans Braun and Rafael Abela, were among the participants, and a major concern of theirs was staying within the budget. The project scientists, on the other hand, often placed dreams ahead of finances.

And who came out on top?

I have repeatedly seen that when the money is short and one is forced to rethink strategy, the science actually improves.

When the ideas flow, how does one check their feasibility?

We always need to ask the questions: Does our technology fit the proposed application? Is SwissFEL the correct solution to the problem at hand? How can the capabilities of SwissFEL be adapted to increase its usefulness?

There were a series of Workshops, which filled your walls with posters.

Yes, particular scientific topics were selected, and a wide range of participants presented their ideas. Each group prepared a poster, summarizing the scientific questions and the demands they place on the SwissFEL machine. I have kept all the posters, and they have been collected in a booklet. When asked for a scientific justification for spending hundreds of million Francs on this facility, I roll out the posters. The experiments they describe make a convincing case.

Which are the scientific themes that make the most convincing case for SwissFEL?

In my opinion, SwissFEL will have three principal fields of applications: information technology, human health and chemical catalysis. Research at this facility will help us develop new materials and nanostructures for realizing faster, more powerful computers. And by clarifying the structure and dynamics of vitally important biological molecules, it will aid in the realization of new pharmaceuticals. Finally, there is catalysis.

Catalysis is a favorite topic of yours. What can SwissFEL contribute?

Catalysis is the “dance of atoms on a surface”. The most famous surface chemical reaction is the Haber-Bosch process for producing ammonia, the basis for artificial fertilizer. A heated iron surface is able to rearrange the atoms of nitrogen and hydrogen to form ammonia, but the process still requires large amounts of energy. The reaction feeds 40% of the world’s population, and the Aswan dam in Egypt was built to drive it. But at the atomic scale, the Haber-Bosch process is still incompletely understood. When we can follow the atomic dance in time and space, we can make this and related catalytic reactions more specific and efficient.

After years of planning, construction has finally begun.

Yes, finally. The facility is designed to accommodate at least three X-ray lasers, which were named for the Three Musketeers. First we will build the hard X-ray line Aramis, whose accelerator technology is the most challenging. Hopefully, after a successful startup, we will be able to add Athos and Porthos.

What would be your dream scenario for SwissFEL?

I want SwissFEL to be a European focus for the realization of artificial photosynthesis. It could aid in the development of methods by which sunlight can be directly converted into chemical energy.

One would make fuel with solar energy.

Yes. Switzerland and the other developed countries of the world must contribute to an energy strategy with a time horizon beyond 2050. What will be our alternatives when we no longer can burn oil and coal? We need chemical fuels which can be stored and transported and which are CO2 neutral. SwissFEL can help us to develop them.

Text: Alexandra von Ascheraden

Fenster zur Forschung 02/2013

in German

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