New SwissFEL soft X-ray endstation welcomes first users

Maloja is go. On Wednesday, 23rd March 2022, first user experiments began at the Maloja endstation, which enables explorations into atomic, molecular and optical physics and chemical dynamics. These user experiments mark a double first, not only for Maloja but also for the second, soft X-ray beamline of the SwissFEL, Athos.

Following two years of tireless development, Maloja is beginning to yield its scientific fruits. Developed in parallel with soft X-ray beamline Athos, Maloja is the first endstation to be up and running, and takes advantage of advanced beam parameters, namely, very short pulses, two colour pulses and pump-probe experiments. A key feature of the Maloja endstation is its modular nature, enabling straightforward exchange of chambers and tailoring to individual experimental requirements.

“Because of its flexible design, a wide variety of investigations are possible at Maloja, such as time-resolved measurements of electronic structure changes, non-linear X-ray spectroscopy or research into gas-phase atoms or nanoparticles. I’m really excited to see the diverse science that future users will turn up with,” enthuses Kirsten Schnorr, lead scientist at the Maloja endstation.

Work began on the Maloja project in 2019, with the COVID pandemic striking a few months after first hardware deliveries. With staff working night shifts to create ‘time-dimensional social distancing’, in June 2020 first light entered the Maloja endstation. This heralded the beginning of commissioning experiments and a very close collaboration between the Maloja team and accelerator groups as, step-by-step, the teams developed not only the Maloja endstation, but also a whole new branch of the SwissFEL: Athos.

Read more on the PSI website

Image: Members of Nanostructures and Ultrafast X-ray Science Group, including Daniela Rupp and Mario Sauppe (3rd and 4th from L) together with the Maloja team and Christoph Bostedt (far R) during the beamtime

Credit: Alessandro Colombo

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