Transcript Mark Rivers: Introduction

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
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)
X-ray No
Microprobe
ID-C style in
Figure Error!
text ofat Station
specified
document.-1: Downstream view of the X-ray
Microprobe apparatus installed in station 13-IDC showing KB microfocusing system, optical
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
O
Low Temperature
2.35Å
Cu2+
O
1.96Å
Cu 495oC
Cl
2.09Å
Cu1+
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)
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)
X-ray Tomograpy at Station BM-D
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
Differential Absorption Tomography
8mm diameter sand column with aqueous phase containing Cs and
organic phase containing I. (Clint Willson, LSU)
32.5 keV, below I and Cs K
absorption edges
33.2 keV, above I and below Cs K
absorption edges
33.2 - 32.5 keV, showing distribution
of I in the organic phase
36.0 keV, above I and Cs K
absorption edges
36.0 - 33.2, showing distribution of Cs
in the aqueous phase