A class of techniques in crystal spectroscopy wherein an ionization chamber (an X-ray detector) is appropriately placed to detect the reflected X-rays after undergoing Bragg scattering which is the scattering of X-rays or neutrons by the regularly spaced atoms in a crystal, for which constructive interference occurs only at definite angles called Bragg angles (angles between an incident X-ray beam and a set of crystal planes for which the secondary radiation displays maximum intensity as a result of constructive interference).

"Bragg scattering" and "Bragg angles" are named after, Sir William Henry Bragg (1862–1942), and his son, Sir William Lawrence Bragg (1890–1971); English physicists and Nobel prize winners in 1915.