Indexing of superimposed Laue diffraction patterns using a dictionary-branch-bound approach

Area of Science:

• Materials Science
• Crystallography
• Diffraction Physics

Background:

• X-ray Laue diffraction is crucial for analyzing crystallographic orientation and strain in materials.
• Current methods struggle with indexing multiple diffraction patterns simultaneously.
• Indexing limitations hinder comprehensive analysis of polycrystalline materials.

Purpose of the Study:

• Introduce a novel method, dictionary-branch-bound (DBB), for simultaneous crystallographic orientation determination.
• Address the limitations of existing methods in handling multiple Laue diffraction patterns.
• Validate the robustness and accuracy of DBB for complex diffraction data.

Main Methods:

• Developed the dictionary-branch-bound (DBB) algorithm.
• Utilized simulated X-ray Laue diffraction data with varying numbers of crystals (up to 100).
• Introduced noise, missing spots, and fake spots to test DBB's resilience and accuracy.

Main Results:

• DBB achieved perfect indexing with a mean angular error below 0.08° in most simulations.
• The method demonstrated robustness against added noise and missing/fake diffraction spots.
• Successful application to synchrotron microdiffraction data confirmed practical utility.

Conclusions:

• The dictionary-branch-bound (DBB) method offers a significant advancement for analyzing X-ray Laue diffraction data.
• DBB enables accurate and simultaneous determination of multiple crystallographic orientations.
• Provides practical guidelines for experimental implementation, enhancing materials characterization capabilities.