Texture Analysis  Implementation And Use

Texture Analysis  Implementation and Use Ronald J. Pandol Mentor: Apurva Mehta Stanford Synchrotron Radiation Lightsource, SULI Student

August 13, 2009

What is (crystalline) texture?

Mouse enamel, magnetotactic bacterium, abalone aragonite platelets, and sponge spicule each have texture.

Outline

Motivation Diraction physics Representation of texture Results from Cu sample Plans for future development

Basic Diraction Physics Bragg Diraction

Basic Diraction Physics

Outline

Motivation Diraction physics Representation of texture Results from Cu sample Plans for future development

How is texture represented? Pole Figures A planar projection of the diraction image Superposition of diraction rings recorded at dierent goniometer angles, with an equal area projection Point intensities proportional to the density of points on the reciprocal sphere

Basic Diraction Physics

The projection of the diraction rings onto a planar surface, with the rotation of the sample, gives a pole gure. Each ring location corresponds to a dierent pole gure

Studying texture at SSRL The x-ray sources at SSRL and beamline facilities provide a suitable laboratory for texture analysis.

Experimentation at SSRL would benet from a texture analysis system.

Studying texture at SSRL The x-ray sources at SSRL and beamline facilities provide a suitable laboratory for texture analysis.

Experimentation at SSRL would benet from a texture analysis system.

Diraction geometry

{χ, θ, ∆} → {φ, ψ}

Pole gures  projections of the reciprocal sphere

From the 2D pole gures, the 3D texture orientation space must be determined. This is a complex mathematical inversion process similar to tomogrophy. Solutions are not unique.

Outline

Motivation Diraction physics Representation of texture Results from Cu sample Plans for future development

Application of texture analysis procedure

Example diraction image for Cu target sample

Application of texture analysis procedure

Incomplete-interpolated and completed pole gures for Cu diraction Data, 111 index.

Application of texture analysis procedure

Incomplete-interpolated and completed pole gures for Cu diraction Data, 200 index.

Application of texture analysis procedure

Incomplete-interpolated and completed pole gures for Cu diraction Data, 220 index.

Application of texture analysis procedure

Incomplete-interpolated and completed pole gures for Cu diraction Data, 311 index.

Outline

Motivation Diraction physics Representation of texture Results from Cu sample Plans for future development

What next?

Plans for further development: Other pole gure inversion methods may be used. A comparative study may reveal that one algorithm works better for this data set. Complete automation

Questions? SPECIAL THANKS TO-

Apurva Mehta Matt Bibee James (Randy) Groves Marc Davidson Karen Magid

Stanford Linear Accelerator Center Stanford Synchrotron Radiation Lightsource Stanford University Science Undergraduate Laboratory Internships Department of Energy