Scientific Highlights and News
Gas attenuators are important devices providing accurate variation of photon intensity for soft X-ray beamlines. In the SwissFEL ATHOS beamline front-end the space is very limited and an innovative approach has been taken to provide attenuation of three orders of magnitude up to an energy of 1200 eV. Additive manufacturing of a differential pumping system vacuum manifold allowed a triple pumping stage to be realized in a space of less than half a meter. Measurements have shown that the response of the device is as expected from theoretical calculations.
The path to experiments that are unique in the world is now open.
The first endstation at the SwissFEL Athos soft X-ray branch is rapidly developing and on track for first experiments in 2021.
The new beamline at PSI's X-ray free-electron laser SwissFEL will soon be ready for action. In December, Athos delivered laser light for the first time − even sooner than expected, to the delight of the researchers responsible for its construction.
The high brilliance of new X-ray sources such as X-ray Free Electron Laser opens the way to non-linear spectroscopies. These techniques can probe ultrafast matter dynamics that would otherwise be inaccessible. One of these techniques, Transient Grating, involves the creation of a transient excitation grating by crossing X-ray beams on the sample. Scientists at PSI have realized a demonstration of such crossing by using an innovative approach well suited for the hard X-ray regime.
The years of careful planning and construction have paid off: At the newest large-scale research facility of the Paul Scherrer Institute PSI – the X-ray free-electron laser SwissFEL – the first experiment has been carried out successfully. With that, two goals have been achieved: First, a new scientific result is already expected. Second, the interaction of the many individual components of the highly complex facility is being optimised.
The horizontal and vertical offset mirrors are key optical elements for the SwissFEL ARAMIS Beamline. The offset mirrors for example, are used to deflect and steer the x-ray beam into one of the end stations. As the sample position is about 60m from the mirror, very high demands are put on the mirror positioning system in order to deflect the x-ray beam on to the sample with a micro-meter precision. Therefore precise positioning of the mirrors is required, with specifications to move a load of up to 200kg by steps as small as 0.3µm. Not just the positioning must be precise, but also the stability for short term vibrations and long term drifts must be superior.