A5069579847- Radioactive element chemistry and processing
- X-ray Spectroscopy and Fluorescence Analysis
- Nuclear Materials and Properties
- X-ray Diffraction in Crystallography
- Nuclear materials and radiation effects
- Nuclear Physics and Applications
- Radioactive contamination and transfer
- Crystallization and Solubility Studies
- Lanthanide and Transition Metal Complexes
- Advanced X-ray Imaging Techniques
- Analytical chemistry methods development
- Chemical Synthesis and Characterization
- Radioactivity and Radon Measurements
- Electron and X-Ray Spectroscopy Techniques
- Geological and Geochemical Analysis
- Iron oxide chemistry and applications
- Geochemistry and Elemental Analysis
- Geochemistry and Geologic Mapping
- Crystallography and Radiation Phenomena
- Glass properties and applications
- Crystallography and molecular interactions
- Nuclear reactor physics and engineering
- Wastewater Treatment and Nitrogen Removal
- Extraction and Separation Processes
- Chemical and Physical Properties in Aqueous Solutions
International Atomic Energy Agency
2022-2025
University of Manchester
2010-2024
University of Cumbria
2024
University of Duisburg-Essen
2006-2020
Karlsruhe Institute of Technology
2009-2018
Science Oxford
2018
Joint Attosecond Science Laboratory
2017
University of Ottawa
2017
HUN-REN Institute for Nuclear Research
2011-2014
FZI Research Center for Information Technology
2002-2013
During nuclear waste disposal process, radioactive iodine as a fission product can be released. The widespread implementation of sustainable energy thus requires the development efficient stores that have simultaneously high capacity, stability and more importantly, storage density (and hence minimized system volume). Here, we report I2 adsorption in series robust porous metal–organic materials, MFM-300(M) (M = Al, Sc, Fe, In). MFM-300(Sc) exhibits fully reversible uptake 1.54 g g–1, its...
Abstract One of the long standing debates in actinide chemistry is level localization and participation 5 f valence orbitals covalent bonds across series. Here we illuminate role uranium, neptunium plutonium chemical bonding using advanced spectroscopies: M 4,5 HR-XANES 3 d 4 RIXS. Results reveal that are active for uranium neptunium, shown by significant variations their evidenced spectra. In contrast, appear localized surprisingly insensitive to different environments. We envisage this...
The ESRF synchrotron beamline ID19, dedicated to full‐field parallel‐beam imaging techniques such as phase‐contrast and absorption microtomography X‐ray topography, is one of the most versatile instruments its kind. This paper presents key characteristics ID19 in present form, names examples for research development performed on beamline, outlines plans an upgrade coming years, adapt growing needs user community. technical goals envisioned include increase available beam size maximum photon...
CAT-ACT-the hard X-ray beamline for CATalysis and ACTinide/radionuclide research at the KIT synchrotron radiation facility ANKA-is dedicated to spectroscopy, including "flux hungry" photon-in/photon-out correlative techniques combines state-of-the-art optics with a unique infrastructure radionuclide catalysis research. Measurements can be performed photon energies varying between 3.4 keV 55 keV, thus encompassing actinide M- L-edge or potassium K-edge up K-edges of lanthanide series such as...
The paper describes the Rossendorf beamline (ROBL) built by Forschungszentrum at ESRF. ROBL comprises two different and independently operating experimental stations: a radiochemistry laboratory for X-ray absorption spectroscopy of non-sealed radioactive samples general purpose materials research station diffraction reflectometry mainly thin films interfaces modified ion beam techniques.
The x-ray linear dichroism of the uranyl ion (${\mathrm{UO}}_{2}^{2+}$) in uranium ${\mathit{L}}_{3}$-edge extended x-ray-absorption fine structure (EXAFS), and ${\mathit{L}}_{1}$- near-edge (XANES), has been investigated both by experiment theory. A striking polarization dependence is observed experimental XANES EXAFS for an oriented single crystal acetate dihydrate [${\mathrm{UO}}_{2}$(${\mathrm{CH}}_{3}$${\mathrm{CO}}_{2}$${)}_{2}$\ensuremath{\cdot}${2\mathrm{H}}_{2}$O], with vector...
The complexation of Cm(III) and Eu(III) with 2,6-di(5,6-dipropyl-1,2,4-triazin-3-yl)pyridine (n-C3H7-BTP) in nonaqueous organic solution is studied extended X-ray absorption spectroscopy. Bond lengths are the same both complexes. Quantum-chemical calculations performed at different levels support this finding. On other hand, Cm.(n-C3H7-BTP)3 complex formed much lower ligand-to-metal concentration ratio than Eu.(n-C3H7-BTP)3 complex, as shown by time-resolved laser-induced fluorescence This...
X-ray absorption fine structure (XAFS) spectroscopy at the Th L3 edge is applied for characterization of crystalline, anhydrous ThO(2)(cr), microcrystalline ThO(2).xH(2)O(s), amorphous ThO(n)(OH)(4-2n).xH(2)O(am), aqueous Th(IV) solutions, and colloidal suspensions up to p(c)H 3.7. The microcrystalline, possibly hydrated thorium dioxide, formed 1.5-2.5 by precipitation from 16-23 nm dioxide colloids. solubility data determined this solid several orders magnitude lower than values hydroxide...
Motivated by the need for megapixel high definition trace element imaging to capture intricate detail in natural material, together with faster acquisition and improved counting statistics elemental imaging, a large energy‐dispersive detector array called Maia has been developed CSIRO BNL SXRF on XFM beamline at Australian Synchrotron. A 96 prototype demonstrated capacity of system real‐time deconvolution complex spectral data using an embedded implementation Dynamic Analysis method...
Since its inauguration in 2005, the INE-Beamline for actinide research at synchrotron source ANKA (KIT North Campus) provides dedicated instrumentation x-ray spectroscopic characterization of samples and other radioactive materials. R&D work beamline focuses on various aspects nuclear waste disposal within INE's mission to provide scientific basis assessing long-term safety a final repository. The is accessible radiochemistry community through proposal system European Union Integrated...
Ionic radii of actinide(III) cations (from U(III) to Cf(III)) in aqueous solution have been derived for the first time starting from accurate experimental determination ion-water distances obtained by combining extended X-ray absorption fine structure (EXAFS) results and molecular dynamics (MD) structural data. A strong analogy has found between lanthanide actinide series concerning hydration properties. The existence a contraction An-O distance along highlighted, while no decrease number is...
The molecular origin of the selectivity N-donor ligands, such as alkylated bis-triazinyl pyridines (BTPs), for actinide complexation in presence lanthanides is still largely unclear. NMR investigations an Am(nPrBTP)33+ complex with a 15N labelled ligand showed that it exhibits large differences chemical shift coordinating N-atoms comparison to both lanthanide(III) complexes and free ligand. temperature dependence shifts observed this indicates weak paramagnetism. This fact bound nitrogen...
The structures of aqueous M(4+)(aq) and MF(3+)(aq), where M is uranium(IV) or thorium(IV), have been determined by L(III) edge EXAFS using data from solutions 1.5 HClO(4) in which the M(IV) concentrations ranged 0.03 to 0.3 M. A least-squares refinement for aqua ions indicated 10.8 +/- 0.5 water molecules first hydration sphere both M-O bond distances U(IV) Th(IV) 2.42 0.01 2.45 Å, respectively. By considering previous structure information data, we selected N = 10 1 as most likely...
Summary The structure parameters of the Am 3+ aquo ion and Am(III) sorbed onto smectite kaolinite at varying pH are analyzed using EXAFS. An Am-O distance 2.47-2.49Å is found a coordination number 8-9 oxygen atoms observed for its hydration sphere. Combined TRLFS (Cm(III)) EXAFS (Am(III)) results show that An(III) sorbs 4, forming an outer-sphere complex retains complete primary With increasing pH, inner-sphere sorption occurs. overall coordinating actinide remains about same 6, with four...
Summary The solubility of amorphous Th(IV) hydroxide at pH 3.0–13.5 and the aqueous speciation < 4 are investigated in 0.5 M NaCl 25 °C. laser-induced breakdown detection (LIBD) is used to monitor initial formation thorium colloids during coulometric titration 1.2×10 −2 −1.0×10 −5 solutions range 2.7–4.5. accurate limit determined by this method comparable with data measured from undersaturation an X-ray solid precipitated higher dried room temperature. Based on hydrolysis constants...
Pu(IV) oxyhydroxide colloid growth is investigated with XAFS and LIBD. From combined results a model of formation proposed, which leads to face-centered cubic Pu sublattice having cation defects, as observed EXAFS, linear dependency log [Pu(IV)] on −log [H+] slope −2, in accord The solubility for measured LIBD close the lower limit curve from previously reported data.
A high energy resolution x-ray absorption near-edge structure (XANES) spectroscopy study on ${\text{U}}^{4+}$ $({\text{UO}}_{2})$, ${\text{U}}^{5+}$ $([{\text{UO}}_{2}{\text{Py}}_{5}][{\text{KI}}_{2}{\text{Py}}_{2}])$, and ${\text{U}}^{6+}$ $[{\text{UO}}_{2}{({\text{NO}}_{3})}_{2}{({\text{H}}_{2}\text{O})}_{6}]$ demonstrates the potential of this experimental technique for qualitative/semiqualitative quantitative actinide speciation investigations. We observe a pre-edge feature with...
Microbial processes can affect the environmental behavior of redox sensitive radionuclides, and understanding these reactions is essential for safe management radioactive wastes. Neptunium, an alpha-emitting transuranic element, particular importance because its long half-life, high radiotoxicity, relatively solubility as Np(V)O2+ under oxic conditions. Here, we describe experiments to explore biogeochemistry Np where Np(V) was added sediment microcosms with indigenous microorganisms...
The N-donor complexing ligand 2,6-bis(5-(2,2-dimethylpropyl)-1H-pyrazol-3-yl)pyridine (C5-BPP) was synthesized and screened as an extracting agent selective for trivalent actinide cations over lanthanides. C5-BPP extracts Am(III) from up to 1 mol/L HNO3 with a separation factor Eu(III) of approximately 100. Due its good performance agent, the complexation actinides lanthanides studied. solid-state compounds [Ln(C5-BPP)(NO3)3(DMF)] (Ln = Sm(III), Eu(III)) were synthesized, fully...