A. Herring, OSU, uses tomography at 13 BMD to quantify pore scale trapping and to analyze how mechanisms affect the efficiency of capillary trapping of CO2 in saline aquifers.

Tomography at 13 BMD

Study in 'Science' finds missing piece of biogeochemical puzzle in aquifers using 13-ID-E's sulfur spectroscopy capabilities. Details in Argonne's press release

Paper in Science showcases the new sulfur capabilities at 13 IDE

X-ray diffraction patterns from a diamond anvil cell (DAC).

X-ray diffraction is the most powerful technique for crystal structure determination. From left to right, patterns from a single crystal, polychrystalline, nano-cyrstalline and amorphous crystals.

X-ray diffraction patterns from a diamond anvil cell.

High pressure x-ray tomographic microscopy module

The HPXTM module helps researchers study the texture change of their sample under extreme pressure and temperature conditions by collecting in-situ HP/HT 3D x-ray tomographic images.

High Pressure X-ray Tomographic Microscopy Module sitting outside of the 250 ton press in 13 BMD.

Peter Hong, Python Tomography Data Collection Project; Andrea Bryant, Determination of Cr, Ti, & V Valences in Olivine & Pyroxene from Ureilites; Catherine Eng, Design a Low Cost Inelastic X-ray Scattering Analyzer

GSECARS Summer Students 2014

GSECARS is a national user facility
for frontier research in the earth sciences using synchrotron radiation at the
Advanced Photon Source, Argonne National Laboratory.

GSECARS provides earth scientists with access to the high-brilliance hard x-rays from this third-generation synchrotron light source. All principal synchrotron-based analytical techniques in demand by earth scientists are being brought to bear on earth science problems:

  • High-pressure/high-temperature crystallography and spectroscopy using the diamond anvil cell
  • High-pressure/high-temperature crystallography and imaging using the large-volume press
  • Powder, single crystal and interface diffraction
  • Inelastic x-ray scattering
  • X-ray absorption fine structure spectroscopy
  • X-ray fluorescence microprobe analysis
  • Microtomography

The Science Beneath The Scream

“It is a moral imperative to preserve these works for future generations”.   - Jennifer Mass, President, Scientific Analysis of Fine Art, LLC, Professor, Univ of Delaware

This research is designed to solve an urgent problem facing the world’s fine art museums - the disfigurement of treasured Impressionist and early modernist masterpieces due to 100+ years of light exposure resulting in the physical and chemical breakdown and discoloration of the early synthetic pigments in these works. This problem affects literally billions of dollars of our global cultural heritage, including works by Edvard Munch, Henri Matisse, Georges Seurat, Vincent Van Gogh, and Pablo Picasso.  Edvard Munch’s The Scream (c. 1910), belonging to the Munch Museet (Oslo), has regions of paint degradation (fading and flaking cadmium yellow paints) in the sky, the water behind the central figure, and, most disturbingly, the yellow paint used in the face and neck of the central figure has in several brushstrokes faded away completely to white.

The goal of this current study is to elucidate the discoloration mechanisms observed in the two paintings in question using micro-x-ray diffraction (microXRD) and speciation (microXANES) mapping, to determine if these mechanisms can be correlated with the use of indirect wet process synthesized cadmium sulfide (CdS). Click


Science Highlight

Newly constrained temperature bounds will help determine the range of permissible phase assemblages and transport at the core–mantle and inner core–outer core boundaries.

Fig5SM.jpg

Thermal pressure derived from XRD data at high pressure and temperature. Pressures of the data points at 300 K range from 10 GPa to 150 GPa. Solid circles (this study): XRD data taken at 13-ID-D. Empty circles (this study): XRD data taken at 3-ID-B. Black curve (this study): thermal contribution to pressure estimated from equation(5). Grey shaded region: estimated uncertainty of the thermal contribution to pressure. The dashed part of the curve is extrapolated. Resistive heating and optical spectroscopy temperature reading are used in Komabayashi et al. (2009, 2012). fcc-and hcp-Fe’s equations of state from Komabayashi(2014)and Dewaele et al.(2006)are used to determine the pressure.

The melting points of fcc-and hcp-structured Fe0.9Ni0.1and Fe are measured up to 125 GPa using laser heated diamond anvil cells, synchrotron Mössbauer spectroscopy, and a recently developed fast temperature readout spectrometer. The onset of melting is detected by a characteristic drop in the time-integrated synchrotron Mössbauer signal which is sensitive to atomic motion. The thermal pressure experienced by the samples is constrained by X-ray diffraction measurements under high pressures and temperatures. The obtained best-fit melting curves of fcc-structured Fe and Fe0.9Ni0.1 fall within the wide region bounded by previous studies. We are able to derive the γ––ltriple point of Fe and the quasi triple point of Fe0.9Ni0.1 to be 110 ±5 GPa, 3345 ±120 K and 116 ±5 GPa, 3260 ±120 K, respectively. The measured melting temperatures of Fe at similar pressure are slightly higher than those of Fe0.9Ni0.1 while their one sigma uncertainties overlap. Using previously measured phonon density of states of hcp-Fe, we calculate melting curves of hcp-structured Fe and Fe0.9Ni0.1 using our (quasi) triple points as anchors. The extrapolated Fe0.9Ni0.1 melting curve provides an estimate for the upper bound of Earth’s inner core–outer core boundary temperature of 5500 ±200 K. The temperature within the liquid outer core is then approximated with an adiabatic model, which constrains the upper bound of the temperature at the core side of the core–mantle boundary to be 4000 ±200 K. We discuss a potential melting point depression caused by light elements and the implications of the presented core–mantle boundary temperature bounds on phase relations in the lowermost part of the mantle.

Zhang, Dongzhou; Jackson, Jennifer, Zhao, Jiyong; Sturhahn, Wolfgang; Alp, E. Ercan; Hu, Michael Y.; Toellner, Thomas S.; Murphy, Caitlin A.; Prakapenka, Vitali B. (2016) Temperature of Earth’s core constrained from melting of Fe and Fe0.9Ni0.1 at high pressures. Earth and Planetary Science Letters, 447, 72-83. Click