Two scientists who have studied superconductivity and magnetic molecular switching at the Californian X-ray laser LCLS have relocated to PSI.Here,they will contribute to the development of the SwissFEL.It‘s the camera that allows researchers to make extremely rapid processes visible:the X-ray free-electron laser.Currently,however,only three sites worldwide—in the US,Japan and South Korea—have facilities capable of carrying out such measurements.Two current articles in Science and Nature Communications co-authored by researchers now at the Paul Scherrer Institute PSI exemplify the kind of outstanding scientific work that can be carried out at such facilities,enabling new insights into the mechanisms of superconductors and magnetic switching in molecules.The measurements were conducted at the Linac Coherent Light Source(LCLS)free-electron laser in California.Two of the leading authors,Simon Gerber and Henrik Lemke,have now relocated to engage in scientific endeavours at the PSI.Here,they will contribute to the Swiss X-ray free-electron laser(SwissFEL)at which first pilot experiments are scheduled for the end of 2017.They are looking forward to first SwissFEL experiments.As far as Simon Gerber is concerned,X-ray free-electron lasers(XFELs)and their capacity to observe ultrafast processes are key to achieving new insights in many fields.One potential area of application is that of superconductivity,a phenomenon that has long fascinated the physicist and many of his colleagues:over 100 years ago the Dutchman Heike Kamerlingh Onnes discovered that many materials lose their electrical resistance at very low temperatures close to absolute zero at minus 273.15 degrees Celsius,allowing them to conduct electricity without loss of energy.However,in order to achieve this,these materials have to undergo acooling process with liquid helium.If this effect would be achievable at higher temperatures—ideally,at room temperature—much energy could be saved. 查看详细>>

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 PSI researchers,together with aresearch group from the University of Rennes in France,conducted the first in aseries of so-called pilot experiments at SwissFEL between 27 November and 4December 2017.The experiment had one clear scientific goal:to investigate the electrical and magnetic properties of titanium pentoxide nanocrystals.Titanium pentoxide is apotential candidate for electronic components of the future,for example,for rewritable data storage units with high recording density.With suitable laser pulses,nanocrystals of titanium pentoxide can be selectively shifted between two states–electrically conducting and semiconducting.This induced transition is exactly what the researchers investigated in the first experiment with SwissFEL’s high-energy X-ray light pulses. 查看详细>>

X-ray lasers belong to amodern generation of light sources from which scientists in widely different disciplines expect to obtain new knowledge about the structure and function of materials at the atomic level.On the basis of this new knowledge,it could then be possible one day to develop better medicines,more powerful computers or more efficient catalysts for energy transformation.The scientific value of an X-ray laser stands or falls on the quality of the ultra-short X-ray pulses it produces and which researchers use to illuminate their samples.An international team led by scientists from the Paul Scherer Institute,PSI,has now precisely measured these pulses.In so doing,they have laid the foundation for ascientifically optimal utilisation of X-ray lasers–not least,of the planned SwissFEL at PSI.The results of this work have recently been published in the scientific journal Nature Communications. 查看详细>>

Using X-ray laser technology,a team led by researchers of the Paul Scherrer Institute PSI has recorded one of the fastest processes in biology.In doing so,they produced amolecular movie that reveals how the light sensor retinal is activated in aprotein molecule.Such reactions occur in numerous organisms that use the information or energy content of light–they enable certain bacteria to produce energy through photosynthesis,initiate the process of vision in humans and animals,and regulate adaptations to the circadian rhythm.The movie shows for the first time how aprotein efficiently controls the reaction of the embedded light sensor.The images,now published in the journal Science,were captured at the free-electron X-ray laser LCLS at Stanford University in California.Further investigations are planned at SwissFEL,the new free-electron X-ray laser at PSI.Besides the scientists from Switzerland,researchers from Japan,the USA,Germany,Israel,and Sweden took part in this study. 查看详细>>