WOLFRAM|DEMONSTRATIONS PROJECT

Bragg's Law

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angle
frequency
Bragg's law describes the reflection of a monochromatic x-ray beam by two parallel crystalline planes separated by a distance
d
. The difference in path lengths is equal to
2dsinθ
and this determines a necessary condition for constructive interference from a family of parallel planes. The Bragg condition enables spacings between many different sets of crystalline planes to be determined.