Response to Fraser & Wark's comments on A new theory for X-ray diffraction.

Area of Science:

• Crystallography
• Materials Science
• Physics

Background:

• Conventional diffraction theory assumes an infinitely thin Ewald sphere surface.
• Previous criticisms of a new theory stem from a misunderstanding of its core concepts.
• Crystal shape effects are distinct from the predicted diffraction phenomenon.

Purpose of the Study:

• To clarify a new theory of crystal diffraction, addressing prior criticisms.
• To demonstrate the theory's relationship with the Ewald sphere construction.
• To present experimental evidence supporting the new diffraction model.

Main Methods:

• Re-evaluation of diffraction theory based on the Ewald sphere construction.
• Detailed explanation of diffraction pattern formation from stacked planes.
• Experimental validation of predicted persistent intensity outside the Bragg condition.

Main Results:

• The new theory models the Ewald sphere surface as having a finite thickness.
• Persistent intensity is predicted and observed outside the Bragg condition (approx. 10^-5).
• The analysis highlights the incompleteness of previous interpretations of diffraction patterns.

Conclusions:

• The proposed theory offers a more complete interpretation of diffraction patterns than conventional models.
• The concept of a "thick" Ewald sphere surface is experimentally verifiable.
• Understanding this persistent intensity is crucial for accurate diffraction analysis.