First light at Furka: The experiments can begin

It’s another milestone on the path to full operation of the X-ray free-electron laser SwissFEL with five experiment stations in all: “First light” at the experiment station Furka. It clears the way for experimental possibilities that are unique worldwide. Team leader Elia Razzoli explains what the Furka Group is planning to do.

Why is “first light” such an important occasion for your team?

Elia Razzoli: It means we’re in business. Or to be more specific: Now we can begin working on the first experiments.

The general public might imagine that you simply flip a switch, and then the light is there. But presumably it’s not that simple in your case . . .

No, it is a complex task. When we at SwissFEL talk about light, we do not mean visible light, but rather X-ray light with characteristics that are unique in the world. To generate that light, and for research to be able to use it, several teams at PSI have to work together. With the Furka experiment station we are, so to speak, at the end of the food chain. To generate the X-ray light of SwissFEL, electrons must be forced onto a sinuous track with the aid of magnets. In the process, they emit the X-ray light that we need to carry out the actual investigations. The magnets that redirect the electrons in this way are called undulators. And they are precisely what makes the whole thing so difficult, because they have to work exactly in sync; otherwise the X-ray light doesn’t have the quality that we need. The complexity of the system grows exponentially with the number and length of the undulators. That is why first light at Furka is already a masterful technical and organisational feat.

Read more on the PSI website

Image: Members of the team that achieved the milestone at the Furka station of SwissFEL: Eugenio Paris (left), Elia Razzoli, Cristian Svetina (right)

Credit: Paul Scherrer Institute/Mahir Dzambegovic