FEL science is one of the most exciting research fields of our times.

Professor Persis Drell, the former director of SLAC National Accelerator Laboratory (Menlo Park, USA), is currently visiting the Center for Free-Electron Laser Science (CFEL) as a Helmholtz International Fellow (Photo Credit: Linda A. Cicero/Stanford News Service).


Center for Free-Electron Laser Science hosts former SLAC director Persis Drell

By Manuel Gnida

The Center for Free-Electron Laser Science (CFEL) has a prominent visitor. Persis Drell, the former director of SLAC National Accelerator Laboratory (USA), has joined DESY scientist Henry Chapman’s group as a Helmholtz International Fellow. Drell, who led SLAC from September 2007 to October 2012, is a Professor of Physics, Particle Physics, and Astrophysics at Stanford University and SLAC. She will be staying at CFEL until March 2013. CFEL is a scientific collaboration between DESY, the Max Planck Society, and Hamburg University. In this interview, Drell talks about free-electron laser science and the partnership between DESY and SLAC.

Welcome to Hamburg, Persis. You have recently stepped down as SLAC director to return to your position as a faculty member and to find more time for research and teaching. What brings you to DESY?

The first thing I wanted to do after stepping down was to temporarily leave SLAC, get out of town, and let the new director take over without my ghost lingering around. It was important for me to step away and go to a different location. Coming to DESY is a great opportunity for me to learn new things without having the responsibilities and deliverables of a SLAC director. My husband and I have many colleagues at DESY. We feel at home here.

Your research has been concentrating on high-energy physics and particle astrophysics. What are you planning to do at CFEL, a photon science institute?

I am here to learn new science and to enjoy myself. In the last five years at SLAC, I have been following the developments in free-electron laser science very closely. It is one of the most exciting research fields of our times. CFEL is a wonderful place to learn about this new science. Many of the leaders in the field work here, and I constantly meet interesting people. I also find the time to read a lot of papers and indulge myself in science.

DESY and SLAC have been closely collaborating for several decades. How would you describe this successful partnership?

DESY and SLAC share a similar arc of history. They both started out as particle physics laboratories and have been broadening their mission over the years. Experimental high-energy physics is currently centered at the LHC [Large Hadron Collider, Geneva, Switzerland], an outside lab. Therefore, DESY and SLAC have been moving more and more into the field of x-ray science. With the free-electron lasers LCLS at SLAC, FLASH at DESY, and the future European XFEL in Hamburg, both institutes are joint explorers of a new frontier. Of course, there is a healthy competition between the two research centers, but it is outweighed by the numerous collaborations, which run extremely deep on so many levels.

Can you give a few examples?

There is people exchange, for instance, with postdocs at one institute later becoming scientists at the other. The scientific exchange is profound, too. Take the method of hard x-ray self-seeding for x-ray free-electron lasers, for example, which had been invented by DESY scientists and has recently been demonstrated at SLAC. I also remember when CFEL scientist Henry Chapman came over to LCLS for the first time to pursue his exciting research on nanocrystals, and I went to the beamline to watch his work. The two institutes also give each other strategic advice. SLAC scientists like me are members of the DESY Scientific Council, and DESY researchers join SLAC’s Scientific Policy Committee. I think DESY and SLAC understand each other’s challenges very well and like to help each other. Last but not least, there are many personal ties. DESY director Helmut Dosch, for example, is not only a colleague but also a friend of mine.

You mentioned your husband, James Welch, who came with you to Hamburg. What is he working on?

Jim is an accelerator physicist at SLAC. He is collaborating with Winni Decking from DESY’s XFEL Project Group. Together they are working on commissioning plans for the European XFEL.

Persis, we wish you a pleasant stay in Hamburg.

Thank you. I am already having a great time.