The path to experiments that are unique in the world is now open.
Light is essential for life, and for researchers it is also a wonderful tool to better understand the structure of materials.
A new PSI method allows quantum-physical research on materials with the aid of X-ray lasers.
During the past decade, scientists have put high effort to achieve sub-10 nm resolution in X-ray microscopy. Recent developments in high-resolution lithography-based diffractive optics, combined with the extreme stability and precision of the PolLux and HERMES scanning X-ray microscopes, resulted now in a so far unreached resolution of seven nanometers in scanning soft X-ray microscopy. Utilizing this highly precise microscopy technique with the X-ray magnetic circular dichroism effect, dimensionality effects in an ensemble of interacting magnetic nanoparticles can be revealed.
In a joint research effort, an international team of scientists lead by Emmanuelle Jal (Sorbonne Université) performed a time-resolved experiment at the FERMI free-electron laser to disclose the dynamic behavior of two magnetic element of a compount material in only one snapshot. The X-ray Optics and Applications group developed a dedicated optical element for this experiment that is usable with two different photon energies (colors) simultaneously.
The first endstation at the SwissFEL Athos soft X-ray branch is rapidly developing and on track for first experiments in 2021.
In a joint research effort, an international team of scientists lead by Prof. Giovanni de Ninno (University of Nova Gorica, Elettra Sincrotrone Trieste) now demonstrated that an OAM-dependent dichroic effect can be observed on photoelectrons. The photoelectrons are released from a sample of He atoms that is excited by the strong extreme ultraviolet light pulses from the FERMI free electron laser, whereas the orbtial momentum is imprinted with an intense infrared laser pulse. The X-ray Optics and Applications group of PSI supported the team with their experience in the creation of OAM beams and during the experiments.
An international collaboration consisting of metrology and photon diagnostics groups Germany, the U.S.A., Switzerland, and Japan performed a set of cross-calibration measurements of optical properties on the Bernina branch of the Aramis beamline . The collaboration saw the DESY-developed gas detector, a novel diamond detector from Brookhaven, and a room temperature radiometer from AIST in Japan placed at the Bernina end station and measure the absolute intensity of the FEL light as it passed through the optical elements. The cross-calibrated measurements used in conjuction with the photon beam intensity-gas (PBIG) monitor at the front end of the Aramis beamline to characterize the performance of the optical components on the Bernina branch and then compare them to the expected theoretical values. The measurements were performed at photon energies of 6.08 and about 7.22 keV.
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.
Data storage devices based on novel materials are expected to make it possible to record information in a smaller space, at higher speed, and with greater energy efficiency than ever before. Movies shot with the X-ray laser show what happens inside potential new storage media, as well as how the processes by which the material switches between two states can be optimised.