Ewald's sphere 1 Incident Beam 20 20 024 133 111 002 gure 8.2 004 022 222 113 Adapted from Vitalij K.Pecharsky and Peter Y.Zavalij,Fundamentals of Powder Diffraction and Structural Characterization of Materials,2nd Edition,Kluwer Academic Publishers (2009),p.154. 66