„Advanced characterization and control of laser wakefield acceleration“.

„Attosecond photoelectron spectroscopy of electron transport in solids“.

Matthias Fuchs has gone off to California, where he is doing basic research with the radiation from the world’s first Free Electron X-ray laser.

Matthias Fuchs, former PhD student in Prof. Florian Grüner’s research group, has left the Laboratory for Attosecond Physics. The young scientist has gone to Stanford. His PhD work at MPQ was concerned with the construction of a new compact laser-driven X-ray source. At his new workplace in California, the SLAC National Accelerator Laboratory, the world’s first free electron X-ray laser based on conventional technology was finished last year. Matthias is now doing basic research with the radiation produced there, in order to gain new insights into the structure of matter. When interviewed, he related how his new life in Stanford began.

What took you to America?

The USA has much to offer in research. But nature, too, with its diversity is also a great attraction. Also interesting to me is the American way of life. By coming here I hope to broaden my horizon. One of the most decisive factors for coming to the USA was my girlfriend. I met her five years ago during an exchange study course in the States. She lives on the West Coast.

How does the research you did at Munich relate to your new location?

My PhD thesis is concerned with the development of a new X-ray source that can be made very compact with the latest laser technology. My colleagues and I achieved a breakthrough by demonstrating such a source in the soft X-ray regime. But this technology is still in its infancy and needs a lot of development work to utilise it for applications. Stanford is the first to succeed in making a similar source in the hard X-ray regime, a so-called Free Electron Laser (FEL). But the source is based on conventional technology. This gives the laser a length of almost 1.5 kilometres. My colleagues in Munich also want to make such a source, but dimensioned to fit into an ordinary university laboratory. The radiation of the X-ray FEL at Stanford is of hitherto unavailable quality. It allows research in regions previously inaccessible. I have already seen the FEL in action and I am thrilled with this highly complex machine. Nevertheless, I am continually aware of the importance of MPQ’s project. At Stanford you need a car or a bicycle to get from point A to point B along the laser.

What exactly is hard X-radiation good for?

The difference between a Free Electron Laser and previous sources is its X-radiation with a huge number of photons bunched in ultrashort pulses lasting just a few tens of femtoseconds. This now affords the prospect of gaining profound insights into the fundamental structure of matter: It has become possible to resolve matter on both atomic length and time scales. This radiation allows us to measure effects hitherto just predicted by theories that have been the subject of controversy for decades. By virtue of the ultrashort pulses it will be possible to produce “films” of processes on an atomic scale.

So films from the microcosm will be “produced” with x-radiation. That sounds revolutionary?

Yes, such an X-ray source can be applied in a variety of fields, ranging from fundamental questions in physics and applications in chemistry to biology. This radiation will allow us, for example, direct observation of the beginning of chemical reactions time-resolved. This knowledge could later help us to exert a specific influence at the right time on chemical reactions. In biology, for example, it is possible by means of this radiation to characterise proteins in their natural surroundings.

How long do you intend to stay in the USA?

A postdoc position such as I have just taken up lasts two or three years. I am not yet sure whether I shall then return to Germany or look for exciting work here in the States.

How is life with you in the USA?

Stanford is a half-hour drive south of San Francisco in the middle of Silicon Valley, where the relaxed Californian way of life holdsway: This is already obvious from the fact that many houses and apartments are equipped with a pool and large brickwork barbecue facilities. The area nestles between the Pacific in the west and Sierra Nevada with Yosemite National Park in the east. With San Francisco one also has a big multifarious city with all its attractions.

How does America’s research approach compare with Germany’s?

Science is already international anyway – English is also the official language in many German laboratories. Scientists have to compare themselves with international colleagues and work in international collaborations. Working styles world-wide are therefore similar. I haven’t been here long enough to pinpoint typical differences. But there seems to be more positions in science, because, compared with Germany, there are more professors per student at universities here. This improves the prospects for long-term positions in research.

What do you miss away from Germany?

I miss some everyday things such as certain German foods or beer. But with insider tips one can find lots of these foodstuffs or make them oneself. It is a pity there are no beer-gardens or Christmas markets. The cities and people are, of course, also different. American cities tend to sprawl more and often have no historical centre. People here, though, are definitely nice, easy-going and helpful. I think one should not compare too much or live in accordance with set rules. One simply has to adjust a little and take things as they are and then make the best of them. Most of all, I miss my family and friends, because I can no longer just drop by for a quick visit. But with modern communications such as video conferencing they’re not quite out of this world.

Interview: Thorsten Naeser