An Optical Analogue of X-Ray and Electron Diffraction Patterns

THE bubble model developed by Bragg and Nye1 gives a pictorial representation corresponding, with a high degree of probability, to the arrangement of atomic sites within a crystalline material. In order, however, to make further progress with the help of this model, it is desirable to produce an experimental technique which will enable some correspondence between the bubble model and the actual degree of order in the crystal to be established.