Journal of large-scale research facilities, 3, A123 (2017) http://dx.doi.org/10.17815/jlsrf-3-112 Published: 29.11.2017 The KMC-3 XPP beamline at BESSY II Helmholtz-Zentrum Berlin für Materialien und Energie * Instrument Scientists: - Ivo Zizak, Helmholtz-Zentrum Berlin für Materialien und Energie phone: +49 30 8062-12127, email: zizak@helmholtz-berlin.de Abstract: The KMC-3 beamline is installed at teh bending magnet of the BESSY II synchrotron light source. It provides focused beam of monochromatic X-ray light at energies between 2.2 and 14 keV. It is dedicated to two experiments: X-ray Pump Probe (XPP) and CryoEXAFS. 1 Introduction The XPP/KMC-3 is a middle range X-ray beamline providing monochromatic light between 2.2 and 14 keV for di�raction and absorption spectroscopy. Optionally the monochromator can be easilly re- moved from the optical path providing focussed white beam at the sample. Two permanent experi- ments mounted in the experimental hutch are dedicated to time-resolved x-ray di�raction and absorp- tion spectroscopy experiments (EXAFS, XANES). In addition, the beamline equipment comprises an ultrafast laser as a pump source for time-resolved experiments. 2 Instrument Application The KMC3 beamline is rather versatile and may be used for di�erent experiments, including energy dispersive re�ectometry and di�ractometry. However, the main goal is to provide the monochromatic beam for time resolved di�raction and absorption spectroscopy experiments. Typical experiments which can be performed at the beamline are mainly variations or combinations of the two permanent experiments mounted at the beamline: XPP-di�raction and CryoEXAFS. 2.1 X-ray Pump-Probe Di�raction XPP experiment is run by the Joint Research Group between HZB and University Potsdam, Prof M. Bargheer. 80 cm diameter vacuum vessel is mounted around the focal spot of the last mirror. It en- compasses a sample goniometer with a cryostat and slit/pinhole system to precisely tune the footprint *Cite article as: Helmholtz-Zentrum Berlin für Materialien und Energie. (2017). The KMC-3 XPP beamline at BESSY II. Journal of large-scale research facilities, 3, A123. http://dx.doi.org/10.17815/jlsrf-3-112 1 http://jlsrf.org/ http://dx.doi.org/10.17815/jlsrf-3-112 http://dx.doi.org/10.17815/jlsrf-3-112 https://creativecommons.org/licenses/by/4.0/ Journal of large-scale research facilities, 3, A123 (2017) http://dx.doi.org/10.17815/jlsrf-3-112 Figure 1: Optical layout of the KMC3 beamline. at the sample. Pulsed laser beam is introduced into the beamline before the sample chamber, and can be focussed to the same spot at the sample. Di�erent X-ray detectors are mounted outside of the vac- uum and can be rotated up to scattering angle of 90◦ (Helmholtz-Zentrum Berlin für Materialien und Energie, 2016; Iurchuk et al., 2016; Navirian et al., 2014; Roshchupkin et al., 2016; Vadilonga et al., 2017). 2.2 CryoEXAFS Cryo EXAFS is permanently mounted at mobile table, and can be connected to vacuum after the di�rac- tion experiment. Having only several two Be windows in the optical path allows to perform EXAFS and XANES experiments down to K-line of Sulphur (experimentally not yet veri�ed). However, mea- surements were already performed (not yet published) on Potassium K-edge (3.6 keV) and Ruthenium L3-edge (2.8 keV) using user-supplied experimental chambers. Standard EXAFS experiment is mounted in vacuum (optionally He-atmosphere) and works in trans- mission and �uorescence geometry. The experiment is provided by the Cooperative Research Group of Prof. H. Dau, Free University Berlin (Görlin et al., 2016; Zaharieva et al., 2016). 3 Source Source characteristics of the BESSY II dipole magnet 13.2 are summarized in the table 1. 4 Optical Design The optical layout of the beamline is shown in �gure 1. The bending magnet source D 13.1 is sagittaly and meridionaly collimated by the rotational paraboloid mirror M1. It is located at a distance of 16.9 m from the source. The double crystal (DCM) monochromator is located at a distance of 21.9 m from the source. Then the beam is refocused by the rotational paraboloid mirror M2 located at a distance of 24.0 m from the source (Fig. 1). 2 http://dx.doi.org/10.17815/jlsrf-3-112 https://creativecommons.org/licenses/by/4.0/ http://dx.doi.org/10.17815/jlsrf-3-112 Journal of large-scale research facilities, 3, A123 (2017) Electron energy 1.7 GeV Magnetic �eld 1.3 T Bending radius 4.35 m Power (0.3 A, 3×0.41 mrad2) 50 W Critical energy 2.5 keV Source size σx 0.15 mm (electron beam) σy 0.04 mm Source divergence σ ′x 388 µ rad (electron beam) σ ′y 21 µ rad Table 1: Properties of the Dipole D 13.1 source. Figure 2: Energy bandwidth of the monochromatic beam. Figure 3: Comparison of the �ux of the white and monochromatic beam in the focal spot. 3 http://dx.doi.org/10.17815/jlsrf-3-112 https://creativecommons.org/licenses/by/4.0/ Journal of large-scale research facilities, 3, A123 (2017) http://dx.doi.org/10.17815/jlsrf-3-112 Figure 4: The shape of the focal spot at di�erent positions in the experimental hutch. 4.1 Monochromatic beam In normal operation the beamline employs the Si monochromator and both mirrors M1 and M2. This can be used for a wide range of experiments providing a monochromatic, tunable x-ray beam hori- zontally and vertically focused on the sample position. A spatial resolution of about 150 µ m can be achieved in this way over the whole energy range. E nergy resolution is ∆λ /λ ≈ 4525˘5000 depending on the energy (Fig. 2). 4.2 White Beam In this con�guration only the mirror system without the monochromator are in the optical path. The �rst monochromator crystal is vertically translated out of the beam and M2 is lowered 25 mm to receive the white beam. The exit window, as well as the experimental setup must be manually lowered 25 mm to accommodate the white beam. The energy spectra of the beamline in two modes are shown in the �gure 3. Filter di�erentially pumped Capton/Be windows. (Pos. 30 000 mm, experimental hutch). Thickness: Capton: 25µ m, Be 200µ m premonochromator optics Paraboloid of rotation Si / Pt 60nm + Rh 5nm optical surface size: 1200×60 mm2 , θ = 0.3º Monochromator Double-crystal monochromator, angular range -3° - 80° Crystals: Si (111) 30 x 70 mm2 10 mm thick Refocusing optics Paraboloid of rotation Si Pt 60 nm + Rh 5 nm optical surface size: 1200×60 mm2 , θ = 0.3º Diagnostics Ionisation chamber for MOSTAB intensity control and feedback Standard Screen Monitor for beam pro�ling Slits Four-blades slit system S2, not water cooled. (Pos. 23 000 mm) two vertical independent tungsten blades, motorized feedthrough. Maximum aperture: 60 mm x 20 mm Step size 10 µ m Table 2: Optical components and parameters of the KMC-3 beamline. 4 http://dx.doi.org/10.17815/jlsrf-3-112 https://creativecommons.org/licenses/by/4.0/ http://dx.doi.org/10.17815/jlsrf-3-112 Journal of large-scale research facilities, 3, A123 (2017) 5 Technical Data The beamline is built in Ultra-High-Vacuum windowless technique separated from the experiment by 150 µm thick beryllium window. The optical concept incorporates two focusing/refocusing options, which can be used alternatively to provide a large �exibility in terms of desired focal size, energy resolution (Fig. 2) and photon �ux (Fig. 3) for di�erent experiments. Depending on the �ux requirements, experiments can be mounted in focus or at the distance between 1 m and 2 m behind the focus. Permanent di�raction XPP experiment is mounted in focus to match the focus of the pumping laser. CryoEXAFS experiment is mounted 2 m behind the focus to avoid the radiation damages. Figure 4 shows the beam cross section at di�erent distances from the focal spot. Segment H13 Location (Pillar) 15.1 Source D 13.2 Monochromator KMC-3 (FMB Oxford) Energy range 2.2 - 14 keV Energy resolution 1/1000 - 1/5000 Flux ∼ 1 × 1011 photons/s (see Fig. 3) Polarisation horizontal Divergence horizontal 300 mrad Divergence vertical 0.3 mrad Focus size (hor.×vert.) 250 µ m × 120 µ m Distance focus - last valve 200 mm Height Focus over �oor level 1500 mm Free photon beam available Fixed end station two alternating stations Beam available 24 h/d 6 days/week Phone +49 30 8062 14695 Table 3: Technical data of the KMC-3 beamline. References Görlin, M., Chernev, P., Ferreira de Araújo, J., Reier, T., Dresp, S., Paul, B., . . . Strasser, P. (2016). Oxygen Evolution Reaction Dynamics, Faradaic Charge E�ciency, and the Active Metal Redox States of Ni-Fe Oxide Water Splitting Electrocatalysts. Journal of the American Chemical Society, 138(17), 5603-5614. http://dx.doi.org/10.1021/jacs.6b00332 Helmholtz-Zentrum Berlin für Materialien und Energie. (2016). XPP: X-ray pump probe station at BESSY II. Journal of large-scale research facilities, 2, A89. http://dx.doi.org/10.17815/jlsrf-2-82 Iurchuk, V., Schick, D., Bran, J., Colson, D., Forget, A., Halley, D., . . . Kundys, B. (2016, Sep). Op- tical writing of magnetic properties by remanent photostriction. Phys. Rev. Lett., 117, 107403. http://dx.doi.org/10.1103/PhysRevLett.117.107403 Navirian, H. A., Schick, D., Gaal, P., Leitenberger, W., Shayduk, R., & Bargheer, M. (2014). Thermoelastic study of nanolayered structures using time-resolved X-ray di�raction at high repetition rate. Applied Physics Letters, 104(2), 021906. http://dx.doi.org/10.1063/1.4861873 Roshchupkin, D., Ortega, L., Plotitcyna, O., Erko, A., Zizak, I., Vadilonga, S., . . . Leitenberger, W. (2016). Piezoelectric Ca3NbGa3Si2O14 crystal: crystal growth, piezoelectric and acoustic properties. Applied Physics A, 122(8), 753. http://dx.doi.org/10.1007/s00339-016-0279-1 5 http://dx.doi.org/10.17815/jlsrf-3-112 http://dx.doi.org/10.1021/jacs.6b00332 http://dx.doi.org/10.17815/jlsrf-2-82 http://dx.doi.org/10.1103/PhysRevLett.117.107403 http://dx.doi.org/10.1063/1.4861873 http://dx.doi.org/10.1007/s00339-016-0279-1 https://creativecommons.org/licenses/by/4.0/ Journal of large-scale research facilities, 3, A123 (2017) http://dx.doi.org/10.17815/jlsrf-3-112 Vadilonga, S., Zizak, I., Roshchupkin, D., Evgenii, E., Petsiuk, A., Leitenberger, W., & Erko, A. (2017). Observation of sagittal X-ray di�raction by surface acoustic waves in Bragg geometry. Journal of Applied Crystallography, 50(2), 525–530. http://dx.doi.org/10.1107/S1600576717002977 Zaharieva, I., Gonzalez-Flores, D., Asfari, B., Pasquini, C., Mohammadi, M. R., Klingan, K., . . . Dau, H. (2016). Water oxidation catalysis - role of redox and structural dynamics in bi- ological photosynthesis and inorganic manganese oxides. Energy Environ. Sci., 9, 2433-2443. http://dx.doi.org/10.1039/C6EE01222A 6 http://dx.doi.org/10.17815/jlsrf-3-112 http://dx.doi.org/10.1107/S1600576717002977 http://dx.doi.org/10.1039/C6EE01222A https://creativecommons.org/licenses/by/4.0/ Introduction Instrument Application X-ray Pump-Probe Diffraction CryoEXAFS Source Optical Design Monochromatic beam White Beam Technical Data