Figure 1
Vertical cross section through the biprism assembly. The two similar polished diamond bars A and B, cross sections 2 mm × 1 mm, meet along the biprism axis normal to the plane of the drawing. Ray X indicates the direction of X-rays transmitted by the biprism. For minimum deviation, the biprism assembly mirror line (dashed) coincides with direction X, and α1 = α2 = 45°. To obtain greater deviations the assembly is rotated about the biprism axis by angle ρ. |