The 2023 Nobel Prize in Physics recognises attosecond science’s pioneers. Past and future, this field’s evolution is entwined with SwissFEL.
An international research team at SwissFEL of PSI has discovered how an enzyme repairs DNA damage with the help of sunlight.
SwissFEL sheds light on how lattice and atomic spins jiggle together.
Researchers have shown that mirror-image substances – so-called enantiomers – can be better distinguished using helical X-ray light.
Targeted manipulations of an atom's magnetic moment are tricky, as the charge currents used for this process are extremely difficult to control . Now, a consortium of collaborators in Germany, Switzerland, Slovenia and Italy reports on a solution to this problem in the cover page article of Physic Review Letters 128, Vol. 15. As it appears, the magnetization of an atomic gas can be altered by high-power lasers using a patterned wave front. The method is promising for studying and manipulating the magnetic properties of matter at the nanoscale.
In contrast to circular dichroism that is dependent on the polarization, helicoidal dichroism induced by a twisted wave front profile is scarcely known. The first evidence of magnetic helicoidal dichroism has now been observed in an experiment using Spiral Fresnel Zone Plates developed at the Paul Scherrer Institut.
SwissFEL is a compact, high-brilliance, soft and hard X-ray Free Electron Laser (FEL) facility laser composed of two parallel beam lines seeded by a common linear accelerator (LINAC), and a two-bunch photo-injector. For the injector, an innovative dual-photocathode laser scheme has been developed based on state-of-the-art Ytterbium femtosecond laser systems. We just published an overview of the the SwissFEL Photo Cathode Drive Lasers (PCDL) performance, pulse shaping capabilities as well as the versatility of the systems, which allow many different modes of operation of SwissFEL . The full control over the SwissFEL electron bunch properties via the unique architecture of the PCDL will enable in the future the advent of more advanced FEL modes; these modes are, but not restricted to, the generation of single or trains of sub-fs FEL pulses, multi-color FEL and finally the generation of fully coherent X-ray pulses via laser-based seeding.
A novel and noninvasive method for high-energy two-color x-ray FEL emission was demonstrated at SwissFEL. In the experiment, a laser emittance spoiler pulse is overlapped with the primary photocathode laser pulse to locally spoil the beam emittance and inhibit the FEL emission from the central part of the beam, ultimately resulting in X-ray emission at two wavelengths. High spectral stability and the possibility to independently control the duration and intensity ratio between the two-color X-ray pulses is demonstrated. The laser emittance spoiler also enables shot-to-shot selection between one and two-color FEL emission and further, as it does not contribute to beam losses, it is compatible with high repetition-rate FELs.
This article has been selected as the winner of the first Ernest Courant Outstanding Paper Recognition, a honor sponsored by the journal Physical Review Accelerators and Beams (PRAB) and the APS Division of Physics of Beams (DPB). This honor recognizes the most outstanding paper published in PRAB annually.
The authors find using resonant and non-resonant x-ray diffraction on an x-ray free electron laser that the structural distortion and the underlying electronic structure of the charge density wave in TiSe2 show different energetics at ultrafast timescales. This indicates that the lattice distortion stabilizes the charge density wave.