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).

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Brillouin spectroscopy frequency LASER l = 514.5 nm Analyzer Fabry-Perot Interferometer elastic several frequencies Brillouin shifted, VP and VS DAC nB,i0 2sin(*/2) Vi = 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.

Building The Prototype System at U Illinois

Building prototype system in Urbana

BMD-13 hutch before installation of the Brillouin system

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.

X-ray and Brillouin control area for BMD-13

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

Single crystal NaCl (B1) at ~30 GPa (left) and polycrystalline NaCl (B2) at ~53 GPa (right) in DAC in Ne pressure medium NaCl single Ruby 100 μm NaCl poly Au+Pt+NaCl Ruby 100 μm Au+Pt+NaCl

MgO in MEW pressure medium MgO in MEW pressure medium. Typical DAC loading for absolute pressure scale measurements. 100 μm MgO single X-tal Au+Pt Ruby

Single crystal X-ray diffraction and calibration Brillouin spectrum of MgO at ambient pressure

X-ray image and Brillouin spectrum of polycrystalline NaCl in B2 structure collected simultaneously at 35 GPa NaCl Vp NaCl Vs Diamond Vs NaCl Vp Diamond Vs NaCl Vs

X-ray image and Brillouin spectrum of single-crystal NaCl (B1) in Ne at 26 GPa NaCl Vs NaCl Vp Diamond Vs Ne Vp Ne BS

Brillouin spectrum of single crystal MgO in [100] direction in a Diamond anvil cell at 4 GPa. Collection time is 3.3 min. MgOVp MgO Vs MEW mix

COMPRES Jennifer Jackson Dave Mao J Shu Acknowledgments COMPRES Jennifer Jackson Dave Mao J Shu