Brendebach, B.

Dardenne, K.

Denecke, M.A.

Liu, X.

Rothe, J.

Vitova, T.

English

Denecke, M. A.

KITopen

INE – Institut für Nukleare Entsorgungmelissa.denecke@ine.fzk.dejoerg.rothe@ine.fzk.dekathy.dardenne@ine.fzk.detonya.vitova@ine.fzk.deSpatially Resolved Studies : combined µ-XAFS and µ-XRD High Pressure Diamond Anvil Cell (DAC) experiment with 243-AmHigh Resolution X-ray Emission Spectroscopy (HRXES)INE-Beamline CharacteristicsSample positionCCDHexapodIncoming beamFluorescencePhotograph of the crystal benderBeam dimensions at 18.5keV:focal length 3mm,FWHM 33μm horizontal and 37µm verticalK Dardenne, B Brendebach, M A Denecke, X Liu, J Rothe, T VitovaForschungszentrum Karlsruhe, Institut für Nukleare Entsorgung, P.O. Box 3640, D-76021 Karlsruhe, Germany0 50 100 150 200 250 300050100150200250 Horizontal VerticalIntensity u.a.µm50 100 150 200 25050100150200Vertical (µm)Horizontal (µm)5010015020025005010015020050100150200Intensity u.a.Vertical (µm)Horizontal (µm)5.00048.0091.00134.0177.0220.0The INE-Beamline is an experimental synchrotron X-ray station dedicated to actinide speciation investigations related to nuclear waste disposal as well as applied and basic actinide research.INE-Beamline - layout50 μm Be windowRh coated cylindrical Si mirror, vert. collimatingRh coated toroidal Si mirror, hor./vert. focusingDouble crystal monochromatorbending magnetExperimental stage : Controlled areadrawing: U. Herberger, FZK-ISSHRXES improves spectral energy resolution of fluorescence emission by several orders of magnitude. This overcomes limitations of conventional techniques and provides electronic structure information for 4f and 5f elements. HRXES spectrometer setup:Photon fluorescence emission is energy dispersed by a bent Si/Ge crystal and focused onto a position sensitive detector. FWHM of the Fe Kβ1,3 line is ~ 5eV.This work was performed during an ACTINET funded fellowshipOptical hutchOn-site (FZK, KIT north campus), backed by decades of know-how and infrastructure to  handle radioactive materialsAccess to INE laboratories for preparation and characterization of samplesStudies with activities up to 106 times the exemption limit allowedSafe and flexible containment conceptMulti-purpose beamline with modular design of experimental setupsStandard methods monochromatic beamXAFS characterization of bulk speciesXAFS/XRD correlate phases with pair distributionsTEY / FluoXAFS for non-transmission experiments Surface sensitive grazing incidence techniqueGI-XAFS characterization of surface sorbed speciesStanding wave characterization of atomic positions at surfacesSpatial resolution focused beam for ”micro” or µ-techniqueµ-XAFS chemical state imagingµ-XRF elemental mappingµ-XRD identification and distribution mapping of phasesEnergy resolution secondary monochromator (Johann spectrometer)HRXES high resolution X-ray emission spectroscopy RIXS resonant inelastic X-ray scatteringCombination of combined x-ray methods or combination of x-raymethods method & other techniques, e.g., laser spectroscopy, UV-Vis, Raman, etc…Future UpgradesExperimental table withstandard setupPhotograph of the spectrometer in use at the INE-BeamlinePhotograph of the Spectrometer at a different Bragg angleSee poster of Vitova et al. New developments at the INE-Beamline for Actinide Research at ANKAEliminate horizontal beam drift during DCM crystal rotation (i.e., large energy scans) with high precision actuators tuning the second DCM crystal roll position.Extend the microfocus capabilities to confocal irradiation-detection geometry for additional resolution in the third (depth) dimension.First active measurements with the HRXES spectrometer, extension of attainable emission energy range, and upgrade to a new position sensitive detector.Combine the electrochemical cell with UV-Vis spectroscopy signal detection for a secondary in-situ verification of oxidation states.Adapt and test a liquid cell for high temperature, high pressure investigations.Instrumentation development and upgrades planned for the near future at the INE-Beamline are related to optimization of the µ-focus options at the beamline, improvements of the HRXES spectrometer, and development of new sample cells for special user requirements. Specifically are planned:In-situ Studies : electrochemical cellElectrochemical cell in use at the INE-BeamlineXANES spectra of different stabilized oxidation states of 237-Np recorded in fluorescence mode17580 17600 17620 17640 176600.00.20.40.60.81.01.21.41.61.82.0  norm. absorption [a.u.]energy [eV] Np(III) Np(IV) Np(V) Np(VI)Np(V) = 17614.0eVΔE Np (V-III) ≈ + 3eVΔE Np (V-IV) ≈ - 1eVΔE Np (V-VI) ≈ + 2eVEdge calibration: Zr K at 17.998keV-0.3 VAg/AgCl+0.2 VAg/AgCl+ 1.0 VAg/AgCl-10010203040502 3 4 5 6 7 8 9 10k [Å-1]k3χ(k)NpIIINpIVNpVI00,010,020,030,040,050 1 2 3 4 5R-Δ [Å] FT magnitude2 Oax1.75 Å5 Oeq at 2.42 Å9 O at 2.52 ÅFourier transform data & best fits using single scattering oxygen shells10 O at 2.37 Å- exhaustive electrolyses for every valence- no more changes observed on XANES spectraNp(V)  Np(III)                  Np(IV)                   Np(VI)  Characterization of a new single bounce capillary (SBC) at 18.5keV by registering the beam spot at the focal distance with an X-ray camera. This SBC is specially designed to adapt to the high horizontal divergence of the beam.Camera outputDigitized beam intensity cross-section and 3D viewSingle-bounce capillary installed at the INE-Beamline for DAC experiment243-Am phase transitions from the AmI phase (dhcp), to AmII (fcc), to AmIII (face centered orthorhombic Fddd) to the highest known pressure AmIV phase (Pnma) at nominal pressure up to 25 GPa in a high pressure DAC are studied. At discrete pressures an XRD pattern is recorded to validate the Am phase and an Am L3 edge XAFS spectrum is recorded in transmission geometry. Setup for µ-XASSetup for µ-XRD XRD ring pattern of the AmI (dhcp) phase left and AmIII phase right, exposure time 5min at 18.5keV(λ = 0.670185 Å)The pressure inside the DAC is measured by in situ monitoring of wavelength changes in the fluorescence emission line of a ruby crystal.Camera in SBC focus50µmThis high pressure Am experiment  is a cooperation with the European Joint Research Centre Institute for Transuranium Elements (ITU) ; G Lander, S Heathman and S. Surblé.Acknowledgements : Cooperation with FZK-ISS, especially S Mangold and T Spangenberg, is acknowledged with gratitude. Colleagues from FZK-INE responsible for in-house projects are acknowledged, namely E Soballa, C Marquardt, and N Banik. Part of the INE-Beamline development is a contractual cooperation between FZK-INE and the Physikalisches Institut, Bonn University. The microfocus upgrade of the INE-Beamline is supported by ACTINET (JP 04-09).Characteristic spectral shapes and energies and relative edge energy shifts:Ge(422) crystal pair in DCM EXAFS recording afterAn electrochemical cell for in situ XAFS investigation of redox sensitive systems has been developed and, following successful tests with inactive Se, used for investigations of the redox chemistry of radioactive 237-Np. Np L3-edge XANES and EXAFS of pure 237-Np species prepared electrochemically in the same solution are recorded. A 1mM 237-Np solution in 1M HClO4 is used as start point.18450 18500 18550 18600 186500.00.20.40.60.81.01.21.4 20.4 GPa 13.2 GPa 1.8 GPa  normalized absorptionenergy [eV]Am L3 edge XAFS spectra for three different pressureDiagram extracted from XRD ring pattern for the AmI (dhcp) phase 12 16 20 24 28 32020000400006000080000100000120000140000Intensity a.u.2theta (°)

New developments at the INE-beamline for actinide research at ANKA

https://publikationen.bibliothek.kit.edu/120077359/3815583

New developments at the INE-beamline for actinide research at ANKA

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