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Problems with Bragg-Brentano diffractometer geometry Multilayer optics
| Date post: | 25-Dec-2015 |
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Problems with Bragg-Brentano diffractometer geometryProblems with Bragg-Brentano diffractometer geometry
Multilayer opticsMultilayer optics
Problems with Bragg-Brentano diffractometer geometry
axial divergenceflat specimen errorspecimen transparency
errorspecimen displacement
error
Problems with Bragg-Brentano diffractometer geometry
axial divergenceflat specimen errorspecimen transparency
errorspecimen displacement
error
Multilayer opticsMultilayer optics
Problems with Bragg-Brentano diffractometer geometrydisappear w/ parallel beam geometry
Problems with Bragg-Brentano diffractometer geometrydisappear w/ parallel beam geometry
Multilayer opticsMultilayer optics
Problems with Bragg-Brentano diffractometer geometrydisappear w/ parallel beam geometry
Even irregularly shaped specimens OK
Can also increase beam intensity
Problems with Bragg-Brentano diffractometer geometrydisappear w/ parallel beam geometry
Even irregularly shaped specimens OK
Can also increase beam intensity
Multilayer opticsMultilayer optics
Problems with Bragg-Brentano diffractometer geometrydisappear w/ parallel beam geometry
Even irregularly shaped specimens OK
Can also increase beam intensity - due to larger capture angle
Problems with Bragg-Brentano diffractometer geometrydisappear w/ parallel beam geometry
Even irregularly shaped specimens OK
Can also increase beam intensity - due to larger capture angle
Multilayer opticsMultilayer optics
Problems with Bragg-Brentano diffractometer geometrydisappear w/ parallel beam geometry
Even irregularly shaped specimens OK
Can also increase beam intensity - due to larger capture angle
More monochromatic
Problems with Bragg-Brentano diffractometer geometrydisappear w/ parallel beam geometry
Even irregularly shaped specimens OK
Can also increase beam intensity - due to larger capture angle
More monochromatic
Multilayer opticsMultilayer optics
Alternate setupAlternate setup
Multilayer opticsMultilayer optics
Alternate setup
increased resolutionreduced fluorescence from specimen
Alternate setup
increased resolutionreduced fluorescence from specimen
Multilayer opticsMultilayer optics
Looks like thisLooks like this
Multilayer opticsMultilayer optics
How does it work?How does it work?
From Principles, Performance and Applications of Multilayer OpticsSrivatsan Seshadri, Osmic, Inc.
Multilayer opticsMultilayer optics
How does it work?How does it work?
From Principles, Performance and Applications of Multilayer OpticsSrivatsan Seshadri, Osmic, Inc.
Multilayer opticsMultilayer optics
How does it work?How does it work?
From Principles, Performance and Applications of Multilayer OpticsSrivatsan Seshadri, Osmic, Inc.
Multilayer opticsMultilayer optics
How does it work?How does it work?
Performance characterized by rocking curve - fixed 2, rotatesPerformance characterized by rocking curve - fixed 2, rotates
From Principles, Performance and Applications of Multilayer OpticsSrivatsan Seshadri, Osmic, Inc.
Multilayer opticsMultilayer optics
Multilayer opticsMultilayer optics
How does it work?How does it work?
Performance characterized by rocking curve - fixed 2, rotatessmaller d, lower Z --> more penetration --> narrower curve
Performance characterized by rocking curve - fixed 2, rotatessmaller d, lower Z --> more penetration --> narrower curve
γ - ratio of the thickness of heavy material to thickness of bi-layer
Low γ multilayer has narrower rocking curve; higher γ multilayer has wider rocking curve
γ - ratio of the thickness of heavy material to thickness of bi-layer
Low γ multilayer has narrower rocking curve; higher γ multilayer has wider rocking curve
Multilayer opticsMultilayer optics
γ - ratio of the thickness of heavy material to thickness of bi-layer
Low γ multilayer has narrower rocking curve; higher γ multilayer has wider rocking curve
Highest reflectivity can be achieved at specific γ, but dependent on coating materials
γ - ratio of the thickness of heavy material to thickness of bi-layer
Low γ multilayer has narrower rocking curve; higher γ multilayer has wider rocking curve
Highest reflectivity can be achieved at specific γ, but dependent on coating materials
Multilayer opticsMultilayer optics
40
60
80
100
0 0.2 0.4 0.6
Thickness ratio of heavy layer and bi-layer
R ( in %) W/B4C, 70 layers
Depth graded coatingDepth graded coating
Yields broadened x-ray spectrumYields broadened x-ray spectrum
From Principles, Performance and Applications of Multilayer OpticsSrivatsan Seshadri, Osmic, Inc.
Multilayer opticsMultilayer optics
Laterally graded coatingLaterally graded coating
When combined w/ curved substrate, can focusWhen combined w/ curved substrate, can focus
From Principles, Performance and Applications of Multilayer OpticsSrivatsan Seshadri, Osmic, Inc.
Multilayer opticsMultilayer optics
Laterally graded coatingLaterally graded coating
When combined w/ curved substrate, can focus…….or make parallel beam (parabolic surface)When combined w/ curved substrate, can focus…….or make parallel beam (parabolic surface)
From Principles, Performance and Applications of Multilayer OpticsSrivatsan Seshadri, Osmic, Inc.
Multilayer opticsMultilayer optics
