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With ELISA (Enhanced Liquid Interface Spectroscopy and Analysis) a novel infrastructure for the investigation of liquid-vapor and liquid-solid interfaces will be implemented shortly on two new dipole beamlines. The investigation of liquid interfaces under operating conditions will improve the understanding of, e.g., the sequestration of CO2 by the oceans, the uptake and release of trace gases by aerosol droplets and thus enable more precise climate models.
Uniqueness: A combination of X-ray with IR radiation, incident on the sample at the same time and the same location, has attracted strong attention, but has so far not been realized anywhere in the world. The ELISA beamline will be the first of its kind and a true “Alleinstellungsmerkmal” for BESSY II and HZB.
Partners: FHI, TU Darmstadt, HZB

SoTeXS (Soft-to-Tender X-Ray Spectroscopy) is supposed to extend and complete the HZB portfolio for battery research, where currently 12 beamlines contribute with 10 different methods. Both energy storage and the required sustainability in mobility and transport demand novel battery concepts. The use of abundant, environment friendly materials, detailed insights into operating electrochemical cells, and understanding of degradation processes will lead to new, sustainable and more efficient materials for energy storage (in line with the battery 2030+ roadmap “Sustainable batteries of the future “). In particular, a combination of the soft and tender X-ray regime (here: 0.5 – 5keV) is an excellent way to investigate almost all elements relevant for battery applications and their “behaviour” in batteries at work.
Uniqueness: SoTeXS will be designed for metrological investigations together with the PTB, making it highly attractive for industrial research. It completes the battery portfolio, which is about to be consolidated into a battery hub together with PTB and BAM, to facilitate IR spectroscopy, X-ray emission and absorption (UPS, XPS, HAXPES, NEXAFS, EXAFS), Resonant Inelastic Scattering (RIXS), small and wide angle scattering (SAXS, ASAXS, WAXS), imaging and tomography.
Partners: HZB, PTB

Many novel infrastructures allow for a wide range of spectroscopic methods under ambient conditions. However, the important aspect of site heterogeneity, catalytically active impurities or defects across the surface is often missing in integral approaches. A near ambient pressure NAP-LEEM/XPEEM instrument would round off the operando instrument portfolio at BESSY II. As part of the CatLab activities, the MPG has purchased a NAP-LEEM/XPEEM instrument, which combines electron microscopy with a lateral resolution between 8 and 30 nm with photoemission spectroscopy (< 60 meV energy resolution) as an operando tool, focusing on surface reactions in the mbar range at temperatures up to 800°C.
Uniqueness: Combining this instrument with a tunable soft X-ray source would create a worldwide unparalleled instrument. Accommodating it next to SMART and SPEEM would create a complementary spectromicroscopy analysis section for magnetism (SPEEM), high resolution studies of chemically relevant surfaces (SMART) and operando NAP reactions.
Partners: HZB, FHI

ioARPES will be built upon the strengths of BESSY II in angle resolved photoemission for electronic band structure determination, and will provide highest energy and angle (momentum) resolution and improved spatial resolution. In a future transition from transistor-based electronics to versatile quantum-material-based technologies, understanding electronic band structures and their tunability by external stimuli such as electric current, bias voltage, electric fields, temperature or strain is crucial. While ioARPES will not strive for record spatial resolution it puts its strength on operando experiments.
Uniqueness: The versatile application of electric fields, bias voltages, mechanical strain at low temperatures in the laboratory-on-a-chip is the main purpose of the instrument.
Partners: HZB, RHTW Aachen, TU Dresden, IFW, FUB

Ultrafast non-equilibrium dynamics studies aim at controlling material properties near ultimate speed and efficiency limits, developing novel concepts for faster and more efficient devices. Particularly for ultrafast spin dynamics, the present BESSY II Femtoslicing beamline is a world-wide unique research tool, albeit with a rather low energy resolution. Very recent experimental and theoretical work show that higher energy resolution is highly desirable to track not only spin but also electronic excitations and explore spatial inhomogeneity; both seem to play crucial but so far largely unexplored roles in magnetic dynamics. Femto- SpeX-HR aims at enabling these studies.
Uniqueness: The Femtoslicing facility is optimized for magnetic dynamics studies with soft X-rays. As the time structure of competing Free Electron Lasers (FELs) is not well matched, the quality of magnetic dynamics data from FELs is no better than that from Femtoslicing. Uniquely, FemtoSpeX-HR benefits from the optimised research environment for spin and electronic dynamics experiments developed at BESSY II. Laser-based sources for the VUV range, the other competitor, do not provide the needed spectroscopic sensitivity; soft X-ray pulses are the probe of choice.
Partners: HZB, HU Berlin

Presto (operando PV Station) builds on HZB’s worldwide leading role in PV research and is envisioned as a modular endstation for spectroscopy and diffraction experiments on modern and emerging PV materials and their interfaces, up to full solar cells. Research foci are on the identification of bulk and interface defects, as well as quantification of their density, energy levels, formation energy, and passivation behaviour. Presto aims at gaining a comprehensive understanding of critical parameters in PV devices, so that their power conversion efficiency, stability, scalability, and manufacturability can be boosted. The multimodal investigations under device operation conditions, i.e., light exposure (a few suns), electrical biasing, and aging conditions (elevated temperature, humidity, oxidizing agents) push PV research to a new level. It will significantly expand BESSY II’s operando and in-situ capabilities in (HAX)PES, XAS, XRF, IPES, UPS, CFSYS, SPV, and XRD studies.

Uniqueness: While the individual methods are available in numerous large-scale laboratories, the experimental capabilities of Presto are holistic and unprecedented worldwide. In-situ and operando capacity, combined with sample environment and diagnostic sample integrity control, closes the gaps between the present research approaches in the field.
Partners: HZB, HU Berlin

TES detection pushes the powerful soft X-ray spectroscopic tools (XAS, XES, RIXS) to world leading impurity level characterization and unprecedented low concentration systems. Scientific focus is on catalytic active sites, nucleation processes and materials impurities and doping levels. The superconducting bolometer principle achieves energy resolved single photon detection. This yields unsurpassed performance for excited molecules, active sites, catalytic thin films and nanostructes but also properties such as spin-flip scattering processes in low-dimensional and dilute systems. MPI-CEC as partner forms a bridge to CatLab: The highest-level characterization possibilities of a TES at a high flux beamline with full polarization control is a real asset for the development of novel catalyst systems.
Uniqueness: The investigation by XAS, XES and RIXS with full polarization control of systems with minute amount materials in solids and liquids will be unique at BESSY II.
Partners: MPI-CEC, HZB

Not just since the Corona pandemic, the importance of protein crystallography in medical research has been obvious. With more than 2500 structures in the Protein Data Bank, BL14.1 is one of the most productive stations in Europe. Building on this success, higher throughput (roughly 500 crystals in 24 hours) capabilities by increasing the beamline flux significantly (x25) is desirable and achievable using a new double multilayer monochromator. The photon flux increase will be complemented with further automation efforts and meta data handling towards a fully automatic (unattended) data collection operation.
Uniqueness: BL14.1ex opens avenues towards new crystallographic methods, such as the synchrotron based serial crystallography (SSX) method, which will be of the greatest importance for a future BESSY III MX-beamline.
Partners: HZB