1. Shining Synchrotron Light on Supercritical Fluids Alan J. Anderson St. Francis Xavier University

2. The Hydrothermal Diamond Anvil Cell HDAC

3. Hydrothermal Diamond Anvil Cell (HDAC)

5. Grooves Sample Chamber Re Gasket Different Diamond Anvil Configurations

6. Surface Profilometry Average depth 47.48 μm Volume 3.55 X 10 6 µm 3 FIB Milling of Diamond Anvil

7. Aqueous solution Vapor bubble HDAC Sample Chamber at 25 o C 0.2 mm

8. Liquid Vapor Isochores 0.80 0.71 0.58 0.32 ρ = 0.87

10. Synchrotron X-ray Micro- and Nanoprobes

11. Canadian Light Source Inc.

13. Detector

14. VaporLiquid Path of Incident X-rays Path of Fluorescence X-rays to the Detector Solution in Sample Chamber @ 25 ºC 300 µm Diamond Anvil

15. X-ray Fluorescence Imaging and Quantitative Analysis

16. Map showing the distribution of Ta 2 O 5 particles in 5% HF at 25 ºC (HDAC 116) Map showing the distribution of Ta in 5% HF at 360°C (HDAC 116) Solid Ta 2 O 5 Particles 100 µm

17. Ta 2 O 5 Dissolved in 5% HF HDAC 116 @ 360°C (ρ = 0.566) 10,700 μg mL -1 Ta HDAC 110 @ 350°C (ρ = 0.575) 7,400 µg mL -1 Ta Ta Standard (1000 µg mL -1 ) HDAC 110 @ 360°C (ρ = 0.575) HDAC 116 @ 400°C (ρ = 0.504) Ta L β1 Fe K β1 Fe K α1 Ta L α1 Energy (keV) Intensity

18. Time resolved analysis - Pb in aqueous fluid during interaction with partially metamict zircon (ZrSiO 4 ) at 300 o C

19. X-ray Absorption Spectroscopy XAS Resolving the local structure of metals in SCW

20. X-ray Absorption Fine Structure (XAFS)

23. Summary Synchrotron – based techniques Monitor SCW – material interaction Resolve the local structure of aqueous metal complexes Solubility of selected oxides

24. Raman spectroscopy Raman system HDAC on the microscope

25. Energy (keV) 7.0 7.5 8.0 8.5 9.0 9.5 10.0 10.5 11.0 11.5 12.0 12.5 Re L lines Ta L lines Interferences in X-ray Emission Spectra

26. Energy (keV) Counts Sample Contamination from Re Gasket

27. CH 4 Sample Contamination from Gasket Reaction with Diamond

28. X-ray Diffraction

29. In situ XRD Wu et al. (1997) Dehydration & Rehydration of Montmorillonite Reversible changes in lattice dimensions