Rigg
Definition (Noun)
an area of higher ground in mountain valley
Bragg law,
in physics, the relation between the spacing of atomic planes in crystals and the angles of incidence at which these planes produce the most intense reflections of electromagnetic radiations, such as X-rays and gamma rays, and particle waves, such as those associated with electrons and neutrons. For maximum intensity of reflected wave trains, they must stay in phase to produce constructive interference, in which corresponding points of a wave (e.g., its crests or troughs) arrive at a point simultaneously. The Bragg law was first formulated by Lawrence Bragg, an English physicistThe Bragg law is useful for measuring wavelengths and for determining the lattice spacings of crystals.
https:// www.britannica.com/science/Bragg-law