Laser Heated Diamond Anvil Cell

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COMPRES annual meeting June 2005
Laser Heated Diamond Anvil Cell
Thomas Duffy, Princeton University Guoyin Shen,
GSECARS, University of Chicago Dion Heinz,
University of Chicago Andy Campbell, University
of Chicago/University of Maryland Acknowledgement
s A. Kubo, S. Shieh, B. Kiefer, V. Prakapenka
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Laser heating facilities in wide use at
synchrotrons -- Advanced Photon Source
GSECARS, HPCAT, SRICAT -- ESRF, SPring-8, ALS,
NSLS Mainly variants of near-IR laser,
double-sided heating design of G. Shen and
colleagues, RSI, 2001. CO2 laser heating
systems -- Advantages large focal spot, no
absorber so avoid chemical reactions and
diffraction interference -- Problems heating
limited to lt40 GPa?, diamond damage, mainly
1-side only Sample environment (Laser heating
workshop March 2004) -Temperature
gradients - Design of heating geometry -Thermal
pressure effects - P/T standards
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Selected Activities for 2004-2005 3/04 Laser
heating workshop at APS (60 participants) 7/04
Andy Campbell joins project as research
associate (50) 8/04-4/05 Completion of system
design and procurement of components including
CO2 laser 11/04 3/05 Princeton/Chicago
collaborative beamtime at 13-ID-D 2/05 Safety
features completed and protocol finalized for CO2
laser system in GSCEARS laser lab 2/05-6/05 Test
ing of system design and benchtop experimentation
with optical layouts 7/05 Andy Campbell becomes
Asst. Prof. U. of Maryland Search for
replacement ongoing
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GSECARS single-sided CO2 laser heating plan
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Design goals for CO2 system   CO2 laser heating
system for in situ use at APS beamline
13-ID-D Status heating system established and
tested in lab, almost ready for hutch
installation Power adequate for heating Fe-free
silicates in the DAC Status 230 W laser more
than adequate. 50 µm spot in olivine heats at 90
W at 38 GPa with Type I diamonds Heating can be
carried out using either Type 1 or Type II
diamonds. Robust, reliable system without
alignment drift Status Negligible drift in
short term heating. High laser power will require
better DAC cooling to be implemented. Power
stability as great as achievable Status CO2
laser can be operated in CW mode. External power
modulation is done using a polarizer/attenuator.
Motorization of attenuator and feedback loop for
stabilization will be implemented Facilitate
hutch installation by using existing components
wherever appropriate Status CO2 beam delivery
has been designed to be single-sided viewing
optics and temperature measurement will occur on
the other side of the DAC, and will utilize the
system currently in place for YLF laser
heating. Conform to safety requirements at
APS Status Laboratory system interlocked,
keyswitched, and shielded. Guidelines for
alignment and operation have been established and
implemented. Shielding material has been
installed also as a liner to laser enclosure in
13-ID-D hutch.
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Description of CO2 laser heating
components   CO2 laser Synrad model f201. 230
W output power at 10.6 µm 5-25 kHz or CW
Linearly polarized, extinction ratio 1501 high
mode quality (TEM00 98) Diode alignment laser
Edmund. 633 nm Class I (0.9 mW) Beamcombiner
Laser Research Optics. Transmits 10.6 µm 99
reflects 633 nm 85 ZnSe Beam expander Infrared
Optical Products. 2X ZnSe Used to limit beam
divergence Mirrors Ophir and Laser Research
Optics. Au/Cu or Au/Si high reflectivity
(gt99.8) warm up by only 2-3 C at 100
W Attenuator II-VI Inc. Polarizing attenuator
exploits high extinction ratio of laser consists
of 22 ZnSe brewster windows 2001 extinction
water-cooled negligible beam deflection when
rotated currently manual operation but planned
for motorized operation in hutch Laser focussing
lens Ophir or Laser Research Optics. ZnSe
plano-convex, meniscus, and diffractive lenses
have been tested 1.0 dia, 2.5 f.l. PCX lens
currently used spot size in DAC 50 µm Final
mirror Under development. Have been using Ophir
Au/Si, 3 mm thick. Testing custom Au/C mirror,
made by Au coating (APS metrology lab) on glassy
carbon substrate Viewing optics On opposite
side of DAC from CO2 laser beam delivery.
Negligible CO2 beam transmitted through DAC using
type I diamonds thin silicate glass slide can be
installed to block beam if measureable
transmission detected with type II diamonds
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After CO2 laser heating at 37 GPa ol -gt pv mw
100 mm
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Future --Further bench top testing of CO2
heating systemSome modification of design to
adapt to constraints of 13-ID-D diffractometer
setup --By May 06, installation of CO2 laser
heating system in 13-ID-D complete --Commissionin
g of the system during the APS 2006-2 run --
Open to general users for 2006-3 run.
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Other Ongoing Projects -- Finite element
simulations of thermal structure in the
laser-heated diamond cell (Kiefer and Duffy, J.
Appl. Phys., 2005) --Systematic study of thermal
pressure effects and development of new in situ
standards at 20-40 GPa -- Sample
environment -- X-ray fluorescent crystals for
x-ray/heating alignment -- ultrahigh P-T
capabilities Laser heating to 2 MBar
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Kiefer and Duffy, J. Appl. Phys. 2005
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Single Hot Plate
Double Hot Plate
Micro Furnace
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A. Kubo, S. Shieh, T. Duffy, G. Shen, V.
Prakapenka
Y3Al5O12 doped with 0.05 Ce (YAGCe) YAGCe
fluoresces in visible in response to x-ray
excitation 3 ?m positioning of x-ray beam and
heating spot center
Shieh et al., ESPL, 2005
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Thermal pressure -- MgO, Pt, Ar, and ruby --
P18-25 GPa, T 2000 K --Good agreement between
MgO and Pt pressures during and after
heating --thermal pressure in sample heated at
1400 K was 2 GPa at 23 GPa --After heating,
pressure outside sample (ruby) was 2-3 GPa higher
than pressure in heated area
A. Kubo, T. S. Duffy, G. Shen, and V. B.
Prakapenka
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