Advanced Photon Source

GeoSoilEnviroCARS Operate a national user facility at the APS for the conduct of frontier experiments in earth, planetary, soil, and environmental sciences. Supported by DOE-Geosciences and NSF-Earth Sciences Techniques available to the scientific community Microprobe and microspectroscopy Microtomography Surface scattering and spectroscopy Microcrystal and powder diffraction Energy-dispersive and monochromatic diffraction and spectroscopy in the diamond-cell Energy-dispersive diffraction and imaging in a 250 ton multi-anvil press Energy-dispersive and monochromatic diffraction in a 1000 ton press Inelastic scattering in the diamond-cell

Large Volume Press (LVP) High Pressure Research Beamline Scientist: Yanbin Wang Instruments: 250 T LVP on bending magnet source 1000 T LVP on undulator source Applications: High resolution crystallography Structures of glasses and melts Phase equilibrium studies with in-situ P/T determination Time resolved experiments on kinetics of reactions (sub-second) Viscosity measurements by falling sphere technique 1000 ton press in Station ID-D

Diamond Anvil Cell High Pressure Research Beamline Scientist: Guoyin Shen, Vitali Prakapenka Instruments: Diamond Anvil Cell Diffractometer X-ray microfocusing with KB mirrors Double-sided heating with two YLF lasers Optical spectrograph for temperature measurement Brillouin spectrometer in 13-BM-D (new) Raman spectrometer for pressure measurement Applications: Very high pressure (to 360 GPa) Temperature to 7000 K Small sample, volume at high P-T Iron at Earth’s core P-T conditions Melting curves at high pressure High P-T phase diagrams Thermal EOS at high P Laser heated Diamond Anvil Cell Apparatus in Station ID-D

Surface Scattering and Spectroscopy and Microcrystallography Beamline Scientists: Peter Eng, Matt Newville Instruments: General purpose diffractometers for surface and microcrystal diffraction (2 instruments, 13-ID-C, 13-BM-C) X-ray focusing with large KB mirrors CCD and multi-element Ge detectors Applications: Diffraction from water/mineral interfaces Metal sorption to hydrated mineral surfaces Identification of minerals in complex earth materials Structural determination on microcrystals Microcrystal structures under extreme conditions (pressure, temperature) Structures of melts and glasses Chemical speciation of atoms in specific lattice sites Surface Spectroscopy Apparatus in Station ID-C

X-ray Fluorescence Microprobe: MicroXRF and MicroXAFS Beamline Scientists: Steve Sutton, Matt Newville Instruments: X-ray microfocusing to 1 micrometer with KB mirrors Multi-element solid state x-ray detector for high count rates Wavelength dispersive spectrometer for high energy resolution applications Fluorescence microtomography X-ray Microprobe at Station ID-C Applications: Chemical speciation in heterogeneous materials Compositions of buried components (fluid inclusions ) Trace element partitioning studies Compositional mapping (diffusion, sorption, zonation) Compositions of microparticles (oceanic particulates, micrometeorites)

Copper Speciation in Hydrothermal Fluid Inclusions J. Mavrogenes and A. Berry (Australian National University) XAFS spectra identify the stable complexes as [Cu(OH 2 ) 6 ] 2+ at 25˚C, [CuCl 2 ]- at 200˚C, and [CuCl(OH 2 )] at the homogenization temperature of around 400˚C. Change in copper coordination and oxidation state is fully reversible. First direct spectroscopic evidence for vapor-phase Cu speciation - suggest copper is transported in the vapor phase as a neutral chloride complex. Cu 25 o C Cu 495 o C Cu 2+ O O 2.35Å 1.96Å Cl 2.09Å Cu  m Low Temperature High Temperature (Mavrogenes, J.A., A.J. Berry, M. Newville, and S.R. Sutton (2001) Copper speciation in vapor phase fluid inclusions from the Mole Granite, Australia. Am. Mineral., submitted)

Microtomography Beamline Scientists: Mark Rivers, Peter Eng Instruments: Flood-field tomography (conventional CAT scan approach) Fluorescence tomography (pencil beam; element specific) X-ray Tomograpy at Station BM-D Applications: CAT scans with micrometer resolution Elemental specificity using edge tomography and fluorescence tomography Dynamic studies of fluids in rocks and soils Root-soil-micro-organism interactions Micro-structure visualization of rare, precious and fragile objects (soil aggregates, plant tissue, meteorites, fossils)

Microtomography (CAT scan) Same as a medical CAT scan, but with more than 100 times better spatial resolution Allows one to see “inside” an object in 3-D without having to cut it Works by reconstruction of cross sections from a set of “projections” or radiographs, just like normal medical x-ray images Allows study of internal structure of objects which cannot be sectioned because they are: –Too valuable –Too fragile –Too time-consuming

Absorption Tomography Fast –Typically 720 projections to create a 650x650x520 voxel image –10-30 minutes Examples: –Eocene snail fossil, 20 mm tall moviemovie –Pumice sample MovieMovie Identification of glass, quartz, feldspar and oxides possible from known compositions and measured attenuation coefficients –Hydrous glass vesiculation (Don Baker, McGill) Radiography with furnace (movie)movie Tomography after quench (movie)movie

Differential Absorption Tomography Collect 2 absorption data sets, above and below the absorption edge of the element of interest – also fast Requires a substantial change in linear attenuation coefficient due to element of interest –Major elements, not trace elements Example: 2mm capillaries with KI solutions, varying concentration 33.1 keV, below I edge33.2 keV, above I edgeDifference

32.5 keV, below I and Cs K absorption edges 8mm diameter sand column with aqueous phase containing Cs and organic phase containing I. (Clint Willson, LSU) Differential Absorption Tomography 33.2 keV, above I and below Cs K absorption edges 36.0 keV, above I and Cs K absorption edges keV, showing distribution of I in the organic phase , showing distribution of Cs in the aqueous phase