Research Groups and Beamlines
LSF is one of the six laboratories in the Photon Science Division (PSD). The groups in LSF continuously improve x-ray-based methods and instrumentation to enhance their chemical sensitivity and time-resolution. We exploit opportunities from multi-modal approaches to obtain chemical information in multiple dimensions with the goal to obtain full chemical information in space and time. We apply our capabilities to a wide range of scientific domains ranging from fundamental questions in physical chemistry, to environmental and energy sciences, to questions in geochemistry and life sciences.
The Reaction Dynamics group applies valence photoionization to study chemistry in all states and phases, from catalysis, energy storage and conversion, combustion, and pollution abatement to astrochemistry. It strives to understand reaction mechanisms and energetics by revealing elusive and highly reactive intermediates, locating rate-determining transition states, identifying reaction coordinates with the goal of rational reaction design. The group operates the VUV beamline, at the forefront of developing and applying double imaging photoelectron photoion coincidence (i2PEPICO) spectroscopy to deliver accurate energetics data as well as a universal, sensitive, selective and multiplexed detection tool.
The group for In-situ Spectroscopy for Environmental Science operates the PHOENIX beamline (PHOtons for the Exploration of Nature with Imaging and XAFS) in the soft to tender x-ray regime for applications in energy and environmental research. Using an elliptical undulator, which is time-shared with the X-Treme beamline, PHOENIX offers X-ray absorption spectroscopy (XANES, EXAFS), scanning microscopy (2.5-5 micron spotsize) and emission spectroscopy (XES, RIXS). Covering the energy range from 0.3 to 8 keV, PHOENIX provides unique access to the K-edges of low-Z elements (N-Fe) and important L-edges (Ca-La), which are key to environmental science, energy research and catalysis. The groups own research focusses on the development of new X-ray techniques, sample environments (in situ cells, liquid microjet, microfluidics cells), and on crystallization and nucleation studies in aqueous environments under in situ conditions.
The Chemical Imaging group develops and provides unique capabilities at the microXAS beamline for imaging the chemical composition in space and time in a broad range of reactive systems at relevant spatial and temporal length scales. The microXAS beamline is a highly versatile hard x-ray microprobe facility with an in-vacuum hard X-ray undulator. At microXAS, spatially resolved XRF, XRD and XAS are applied as non-destructive chemical probes, while transmission and scattering provide complementary structural information. microXAS holds a pioneering role in implementing chemical tomography approaches, expanding chemical imaging from 2D into the third (and forth) dimension. Chemical tomography is a non-destructive ‘inside view’ into reactive materials. A broad range of scientific communities use microXAS to gain information about the chemical structure and complexity of hierarchical, heterogeneous reactive materials, including chemical reaction pathways and kinetics. Another specialty of microXAS is the part-time operation as the world-wide only hard x-ray microprobe facility for radioactive samples, in close collaboration with the hot laboratory of the NES division.
The Operando Spectroscopy group applies hard X-ray spectroscopy mostly for chemistry and energy applications. The group is matrixed between the PSD and ENE divisions at PSI and it operates the SuperXAS beamline at a 2.9 Tesla superbend magnet. The beamline hosts a variety of methods including XANES, EXAFS, non-resonant and resonant XES, RIXS and a technique developed in-house: high energy resolution off-resonant spectroscopy (HEROS). The ability of SuperXAS to collect XAS spectra in a few ms (quickXAS) is world leading and allows deciphering reaction mechanisms and reactions. The research of the group is focused on uncovering structure-activity relationships in energy materials, such as (photo-), (electro-) catalysts and batteries. A laser system allows for laser pump–X-ray probe experiments in the ns-µs time range, complimentary to the fs-ps range available at SwissFEL. The time scales available at superXAS allow probing questions from slow degradation processes in e.g. battery materials to fast photo-activation of photo-catalysts.
The Alvra group specializes on ultrafast dynamics in chemical and biological systems using both X-ray scattering and spectroscopy. The two Alvra Prime and Flex instruments are located at the Aramis branch of the SwissFEL, covering the photon energy range from 1.8 to 12.4 keV. The Prime chamber is designed to perform X-ray absorption and emission spectroscopy over the full photon energy range of Aramis, which includes the experimentally challenging tender X-ray regime from 2-5 keV. The Alvra Prime system is designed for X-ray spectroscopy in either vacuum or He environment on liquid or solid samples, as well as for serial femtosecond crystallography (SFX) experiments on proteins. The Flex instrument is designed to accommodate a variety of user-supplied hardware, as well as being the home for a flexible von Hamos-geometry X-ray spectrometer for (resonant) X-ray emission spectroscopy or inelastic X-ray scattering (IXS) measurements. The Alvra group’s research is focused on using the capabilities of Alvra to perform tender and hard X-ray experiments on ultrafast timescales, investigating dynamics ranging from excited-state energy relaxation in solvated molecular species to charge carrier transport and trapping in photocatalytic semiconductor materials.
The Maloja group is designing and constructing the new endstation for non-linear X-ray sciences and single-shot imaging approaches at the new Athos undulator line of SwissFEL. The Maloja endstation is currently part of the Athos project in LAP and it is build in close collaboration between LSF and LAP. We expect first light in the endstation in 2020 and start of user operations in mid 2021. Maloja is located at the soft x-ray branch Athos of SwissFEL and it is designed to take full advantage of the novel intense few to sub-fs soft X-ray pulses (250 eV to 1800 eV) with multiple colors. The endstation targets atomic, molecular and non-linear science with a wide range of experimental techniques, including electron and ion spectrometers as well as large area detectors for ultrafast imaging. A diagnostics suite for x-ray pulse characterization, x-ray / optical cross correlation and expansion capabilities for future non-collinear optics geometries are part of the baseline design.
|Reaction mechanisms in catalysis and combustion, atmospheric and astrochemistry. Detection and assignment of elusive reactive intermediates via valence ionization.
|In-situ Spectroscopy for Environmental Sciences
|Energy and environmental research. Tender x-ray in-situ spectroscopy of low-Z elements, time-resolved measurements, chemical imaging, X-ray emission spectroscopy
|Multi-dimensional multimodal chemical imaging. Hard x-ray microprobe for spectroscopy and diffraction, time-resolved approaches, radioactive samples.
|Operando Spectroscopy (with ENE)
|Heterogeneous catalysis, electrochemistry, photochemistry. Hard X-ray probes for operando spectroscopy including quickEXAFS.
|Photochemistry and photobiology. Femtosecond tender to hard x-ray spectroscopy and diffraction, including serial femtosecond crystallography.
|Maloja group (with LAP)
|Ultrafast and non-linear X-ray sciences, single-shot imaging, time-resolved spectroscopy. Applications in atomic, molecular, and optical physics as well as chemical sciences.