21. December 2015

To the beam tunnel

Large Research Facilities SwissFEL

Since the autumn of 2015, the SwissFEL beam tunnel has been filling up with the machine components for the new PSI large research facility. Piece by piece, the pre-assembled components are being brought to their final destinations.

A tractor and trailer is not an unusual sight in the rural region of Aargau. But since the autumn of 2015, the freight carried by some of them is a little out of the ordinary, as that’s when transportation started for the machine components for the SwissFEL X-ray free-electron laser to the beam tunnel of the new large research facility at PSI.

Parts to create the X-ray light

The beam tunnel is where those parts of the facility are being installed that will create the SwissFEL X-ray light: the injector with the electron source, the linear accelerator and the undulators. The electrons are created and pre-accelerated in the injector, while the linear accelerator is where the necessary additional energy is added and the undulators are responsible for sending them on a slalom path. This then forces the electrons to emit the SwissFEL X-ray light.

Roughly 200 transport journeys

Most of the components are pre-assembled in halls in the surrounding area on granite girders that are each about four metres long. They are then brought to the SwissFEL building piece by piece. It is only the undulators that are completely assembled in the building itself, says Johan Wickström, who coordinates the transportation of the machine components. A total of around 200 transport journeys are planned for the components in the beam tunnel. Approximately one quarter of the beam tunnel has already been filled. By the autumn of 2016, all of the components – from the injector to the undulators – should be assembled and ready in the beam tunnel.

Commissioning in stages

At the same time, the high-performance amplifiers for the injector are being installed on the level above. They will generate the microwave pulses needed to accelerate the electrons created in the injector. Commissioning of the SwissFEL will take place in stages and start in the spring of 2016 with the injector. The first pilot experiments are planned for 2017.

Text: Paul Scherrer Institute/Martina Gröschl
Photos: Paul Scherrer Institute/Markus Fischer

A SwissFEL accelerating structure is brought into the beam tunnel

Camera travels through the (almost) empty SwissFEL

First undulators reach the SwissFEL building