# Bragg's Law (X-Ray Analytical Methods)

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1. Feb 12, 2016

### Kelly Green

1. The problem statement, all variables and given/known data
Explain using word, diagrams, and/or calculations..
(1) Why must n always be <= 2d/λ?
(2) If λ is significantly greater then d, why will no diffraction occur?

2. Relevant equations
Bragg's Law nλ=2dsinθ
n has its maximum when sinθ is 1 (at 90°)

3. The attempt at a solution
I am taking an X-Ray Analytical Methods course. I understand the general concept of Bragg's Law, but am having a hard time answering / proving the two questions above, perhaps I am over thinking it? Any feedback and/or direction would be greatly appreciated.

Last edited: Feb 12, 2016
2. Feb 12, 2016

### Greg Bernhardt

What have you tried and what specifically are you having trouble with?

3. Feb 12, 2016

### Kelly Green

sorry, I didn't put the problem statement in the correct area of the template (edited).

rg: Bragg's Law nλ=2dsinθ - Explain using word, diagrams, and/or calculations..
(1) Why must n always be <= 2d/λ?
(2) If λ is significantly greater then d, why will no diffraction occur?

I understand the concept of constructive and deconstructive interference, but am having a hard time mathematically proving it..