Question

what dose the bragg's law describe?

Answer 1

Bragg's Law: when a monochromatic X-ray light incidents upon a crystal, atoms in lattice scatter the radiation of the same wavelength. The reflected beam will have the maximum intensity at a particular incident angle when the path difference between two reflected waves from two different planes is an integral multiple of the wavelength of X-rays.

It can be expressed by

Path difference = n? = 2dsin?

where n is the order of reflection (represented as an integer), ? presents the wavelength of the incident X-rays, d is the interplanar spacing of the crystal, and ? is the incidence angle.

The principle of Bragg’s law is used in Bragg spectrometer, which can be used to study the structure of crystals and molecules.