Bragg′s Law

When a beam of x-rays strikes a crystal surface in which the layers of atoms or ions are regularly separated, the maximum intensity of the reflected ray occurs when the complement of the angle of incidence, θ, the wavelength of the x-rays, λ, and the distance between layers of atoms or ions, d, are related by the equation where n = an integer λ = wavelength of x-rays [m] θ = angle of incidence of x-rays [radians] d = lattice spacing [m]

See also: Bragg, Sir William Henry, Bragg, Sir William Lawrence, Crystal.