brillouin scattering and synchrotron x-ray measurements at gsecars, advanced photon source:...
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Brillouin Scattering and Synchrotron X-Ray Measurements at GSECARS, Advanced Photon Source:
Simultaneous Measurements of Sound Velocities and Density
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
A COMPRES Infrastructure Development Project
June 2005 Annual Meeting Status
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).
CMB ~2890 km depthCMB ~2890 km depth
Earth’s SurfaceEarth’s Surface
JapanJapanCentral AmericaCentral America
Izu BoninIzu BoninIndonesiaIndonesia
Fiji-TongaFiji-Tonga
(Kárason and Van der Hilst, AGU Monograph, 2000)
Interpretation of global seismic information:Interpretation of global seismic information:
frequency
LASER = 514.5 nm
Analyzer
Fabry-PerotInterferometer
elasticseveral
frequencies
elasticBrillouinshifted, VP and VS
DAC
B,i0
2sin(*/2) Vi =obtain sound velocities (Vi = VP or VS)
Brillouin spectroscopy
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 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.
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
Au+Pt+NaCl
NaClsingle
Ruby
100 μm
NaClpoly
Au+Pt+NaCl
Ruby
100 μm
MgO in MEW pressure medium. Typical DAC loading for absolute pressure scale measurements.
100 μm
MgO single X-tal
Au+PtAu+Pt
Ruby
X-ray image and Brillouin spectrum of polycrystalline NaCl in B2 structure collected simultaneously at 35 GPa
NaCl Vs
NaCl Vp
Diamond Vs
NaCl Vp
NaCl Vs
Diamond Vs
NaCl Vs
NaCl Vp
X-ray image and Brillouin spectrum of single-crystal NaCl (B1) in Ne at 26 GPa
NaCl Vs
NaCl Vs
NaCl Vp
NaCl Vp
Diamond Vs
Diamond Vs
Ne Vp
Ne Vp
Ne BS
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