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 NewvilleInstruments:• 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(OH2)6]2+ at 25˚C, [CuCl2]- at

200˚C, and [CuCl(OH2)] 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 25oC

Cu 495oC

Cu2+

O

O

2.35Å

1.96Å

Cl

2.09ÅCu1+

65m

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 EngInstruments:• 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 movie

– Pumice sample Movie• 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)

• Tomography after quench (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 edge 33.2 keV, above I edge Difference

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

33.2 - 32.5 keV, showing distribution of I in the organic phase

36.0 - 33.2, showing distribution of Cs in the aqueous phase