What are the key ingredients for a successful laser heating experiment at the synchrotron? Guoyin...
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What are the key ingredients for a successful laser heating experiment at the synchrotron? Guoyin Shen CARS, University of Chicago GeoSoilEnviroCARS The University of Chicago Laser heating workshop, March 20, 2004
Transcript of What are the key ingredients for a successful laser heating experiment at the synchrotron? Guoyin...
What are the key ingredientsfor a successful laser heating experiment
at the synchrotron?
Guoyin Shen
CARS, University of Chicago
GeoSoilEnviroCARS The University of Chicago Laser heating workshop, March 20, 2004
Some types of laser heating experiments
* Overcome kinetic barrier* Stress release* In situ phase identification at high P-T* Phase relations (melting)* P-V-T equations of state* Phonons* Electrons* Magnetism
GeoSoilEnviroCARS The University of Chicago Laser heating workshop, March 20, 2004
GeoSoilEnviroCARS The University of Chicago Laser heating workshop, March 20, 2004
DAC
On-line detection
Science
Laser X-ray
Data evaluation
Sample
Off-line detection
GeoSoilEnviroCARS The University of Chicago Laser heating workshop, March 20, 2004
Diamond Anvil Cell
- Allow double sided heating- Have large access opening- Gasket (thickness, energy)- Cooling (stability)
Gasket
2
WC seatDiamond anvil
X-ray transparent seat
GeoSoilEnviroCARS The University of Chicago Laser heating workshop, March 20, 2004
Laser heating system
Type (YLF, CO2)Power distribution (modes)Heating spot sizeStability (short and long term) Pointing stability (laser, optics)Feed back systemTemperature measurement systemUser “friendly”
X-ray beam
EnergySizeCleanliness“Visibility”
GeoSoilEnviroCARS The University of Chicago Laser heating workshop, March 20, 2004
X-ray(5-7 m)
<10 m beam
Sample (>20 m)
Detection
GeoSoilEnviroCARS The University of Chicago Laser heating workshop, March 20, 2004
AlignmentFive path alignment (2+2+1)With coaxial optics, three path alignment (1+1+1)X-ray position (visual image, small marker)No pre-alignment, every cell is uniqueAlignment stability (< 2 m)
Sample environment
Absorption considerationsSelf absorption (metal, semi-transparent) MixtureDouble hot plates
Insulation considerations (medium)Materials (Ar, NaCl, Al2O3, MgO, KCl…)ThicknessDiffraction pattern, absorption, ...
SampleGrain size, thickness, shape (disc)
OthersPressure determinationX-ray alignmentLoading environment
GeoSoilEnviroCARS The University of Chicago Laser heating workshop, March 20, 2004
sampleGasket
laser
medium
X-ray
GeoSoilEnviroCARS The University of Chicago Laser heating workshop, March 20, 2004
Detection
- Atomic structurediffraction, EXAFS,…
- Phononsnuclear inelastic scattering, …
- Electronic structurex-ray Raman, emission, absorption
- MagnetismMössbauer, emission
- Chemical compositionemission, absorption, …
……
GeoSoilEnviroCARS The University of Chicago Laser heating workshop, March 20, 2004
Data evaluation
* Large amount of datanotes (data catcher), software
* “Unexpected” featuresconditions, chemistry, reproducibility
* “Dynamic” experimentson-line analysis
