Problems with Bragg-Brentano diffractometer geometry Multilayer optics.

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