# Bragg diffraction - How to make sense of it ?

1. Jan 25, 2014

### svrphy

Bragg diffraction - How to make sense of it ??

Is there a way to make sense of Diffraction of X Rays without taking recourse to oversimplified concepts like "Reflection of X Rays by parallel planes" which is generally the explanation in most basic physics books. It's been a couple years since I first studied it and i continue to get confused by assertions like reflecting of Photons by atoms. Online sources are also full of it :

http://www-outreach.phy.cam.ac.uk/camphy/xraydiffraction/xraydiffraction7_1.htm
OR
http://chemwiki.ucdavis.edu/Analytical_Chemistry/Instrumental_Analysis/Diffraction/Bragg's_Law

2. Jan 25, 2014

### UltrafastPED

You can start with the Laue equations, which are derived from interference principles used in gratings, and derive the Bragg equation from them: http://www.phys.utk.edu/courses/Fall 2009/physics671/chapter1c.pdf

Or you can start with the fully quantum mechanical Bloch theorem and derive the Bragg equation:
http://www.uni-tuebingen.de/meso/ssscript/blochelectrons.pdf [Broken]

But the Bragg equation is very simple, and very accurate, so I have used it extensively in my electron diffraction work.

Last edited by a moderator: May 6, 2017
3. Jan 26, 2014

### svrphy

I get that. But, is there a way to explain things without relying on mathematical formalism. I mean a general discussion on the physical mechanism.

4. Jan 26, 2014

### UltrafastPED

Read chapter two of this dissertation: http://hdl.handle.net/2027.42/63758

It starts with crystal theory, atomic scattering, and elastic scattering from crystals ... in short, a derivation of diffraction patterns starting from scratch.

5. Jan 27, 2014

### M Quack

This article by P. P. Ewald, one of the founding fathers of x-ray diffraction, give an excellent overview without excessive math.

http://rmp.aps.org/abstract/RMP/v37/i1/p46_1

6. Feb 5, 2014

### svrphy

Thanks for the link. If you have access, could you pls give me the pdf ?

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