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Brillouin Scattering and Synchrotron X-Ray Measurements at GSECARS, Advanced Photon Source: Simultaneous Measurements of Sound Velocities and Density. A COMPRES Infrastructure Development Project June 2005 Annual Meeting Status. Jay D Bass 1 Stanislav V. Sinogeikin 1
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Brillouin Scattering and Synchrotron X-Ray Measurements at GSECARS, Advanced Photon Source: Simultaneous Measurements of Sound Velocities and Density A COMPRES Infrastructure Development Project June 2005 Annual Meeting Status Jay D Bass1 Stanislav V. Sinogeikin1 Vitali B. Prakapenka2 Dmitry L Lakshtanov1 Carmen Sanchez-Valle Guoyin Shen2 Mark Rivers2 1: Geology Dept, University of Illinois, Urbana-Champaign, Urbana IL 61801; 2: GSECARS, University of Chicago, Chicago IL
Goals and motivations for building a Brillouin system at BMD-13 • Simultaneous measurements of: Density by x-ray diffraction Sound velocities by Brillouin scattering • Determination of an absolute pressure scales. • The equation of state and velocities as a function of pressure could be determined without resort to a secondary pressure standard. • Velocity-density measurements under a wide range of P-T conditions. • High-T-P EOS parameters of materials (single crystal elastic constants, velocities, adiabatic and isothermal bulk moduli, shear modulus, and their P-T derivatives; thermal expansion and Gruneisen parameter as a function of P and T) • A central Brillouin facility, open to the entire community and not widely available elsewhere (except in a few specialized labs).
Interpretation of global seismic information: Japan Central America Izu Bonin Indonesia Earth’s Surface Fiji-Tonga CMB ~2890 km depth (Kárason and Van der Hilst, AGU Monograph, 2000)
nB,i0 Vi = 2sin(*/2) LASER DAC l = 514.5 nm Brillouin shifted, VP and VS elastic several frequencies elastic Analyzer Fabry-Perot Interferometer frequency Brillouin spectroscopy obtain sound velocities (Vi = VP or VS)
Key design considerations • User-friendly: possible to operate without being an expert. • Quick setup and break-down of Brillouin experiments • Fast and reliable alignment procedure, requiring minimum setup time. • Complete remote control (of optics and electronics, data collection, outside the hutch • Compatible with both powder and single crystal diffraction techniques • Different scattering geometries : 50, 80, 180 degrees. • Compact ( limited space in beamline station) • Does not interfere with the other experimental techniques on the beamline • Satisfy all laser safety requirements for Class IV laser
Timeline • 2002-2004. Ordering equipment (e.g. Fabry-Perrot interferometer). • Detailed design of the Brillouin system. • Building up prototype at UIUC • Testing , making blueprints, machining parts that could not be purchased. • September 2004. Installing a second level table at BMD-13. Installing Fabry- Perot interferometer in BMD-13. • October 2004. Installing most optical components at BMD-13. • January 2005. Installing laser and permanent translation stages. Collecting the first Brillouin spectrum of standard MgO single crystal on Jan 16, 2005. • February 2005. Commissioning. First measurements in DAC: single crystal-NaCl to 30 GPa, single crystal MgO to 25 GPa; polycrystalline B2-NaCl to 53 GPa. • Summer and fall 2005. Installation of additional components. Simultaneous high-T high-P measurements. Preparation for general users. • 2006. Open for general users.
Schematic diagram and photographs of the Brillouin system installed at sector 13-BMD at APS
Complete Brillouin system combined with X-ray diffraction hardware
Schematic diagram of the Brillouin system installed at sector 13-BMd at APS (Upper level) Permanent optical elements: M - mirror; L - lens; BS - beam splitter; PR - dispersion prism; R - retroreflector; SF - spatial filter; PMT - photo-multiplier tube. Laser beam / image conditioning elements (controllable from outside the hatch, blue boxes): SSh - safety laser shutter; PRot - polarization rotator; LDp - laser beam depolarizer; ICP - intensity control polarized for stalilization beam; IBS – imaging beam splitter; CF - color filter; NDF - neutral density filter. Observation / feedback elements (red boxes): PD - photodiode; VC - video camera; MVC - microscope with video camera. Beam / image alignment elements (yellow boxes): ID - iris diaphragm; ABBS - alignment beam beamsplitter; RBS - retroreflecting beamsplitter
Schematic diagram of the Brillouin system installed at sector 13-BMd at APS (Lower level) Motorized translation components (controllable from outside the hatch, blue boxes): HMTS - horizontal motorized translation stage; VMTS - vertical motorized translation stage; MLFA - motorized laser focusing assembly; MSCA - motorized signal collecting assembly; SPOA - sample positioning and orientation assembly; SL-LB - sample light / light block. Observation / feedback elements (red boxes): VC - video camera; BT - beam target. X-ray components: MAR - MAR Imaging plate; XBS - X-ray beam stop; CS - cleanup slit.
Computer interface for controlling X-ray and Brillouin optics and electronics
Schematic view of simultaneous Brillouin scattering and X-ray diffraction in DAC
Simultaneous X-ray and Brillouin experiments performed in BMD-13 in February 2005 • NaCl in B1 phase to 30 GPa. • MgO to 25 GPa. • Aggregate acoustic velocities, elastic moduli and equation of state of polycrystalline NaCl in B2 phase to 53 GPa. • In all absolute pressure scale experiments gold + ruby (+ platinum + powdered NaCl) were added to experimental charges to cross calibrate these pressure standards against absolute equations of state of NaCl and MgO
Ruby Ruby NaCl single NaCl poly 100 μm 100 μm Au+Pt+NaCl Single crystal NaCl (B1) at ~30 GPa (left) and polycrystalline NaCl (B2) at ~53 GPa (right) in DAC in Nepressure medium Au+Pt+NaCl
MgO single X-tal Au+Pt Au+Pt Ruby 100 μm MgO in MEW pressure medium. Typical DAC loading for absolute pressure scale measurements.
Single crystal X-ray diffraction and calibration Brillouin spectrum of MgO at ambient pressure
NaCl Vp NaCl Vp NaCl Vs NaCl Vs Diamond Vs X-ray image and Brillouin spectrum of polycrystalline NaCl in B2 structure collected simultaneously at 35 GPa NaCl Vp Diamond Vs NaCl Vs
Diamond Vs Diamond Vs NaCl Vp NaCl Vp Ne Vp Ne Vp NaCl Vs NaCl Vs Ne BS Ne BS X-ray image and Brillouin spectrum of single-crystal NaCl (B1) in Ne at 26 GPa
MgOVp MEW mix MgO Vs Brillouin spectrum of single crystal MgO in [100] direction in a Diamond anvil cell at 4 GPa. Collection time is 3.3 min.
Acknowledgments COMPRES Jennifer Jackson Dave Mao J Shu