International
Tables for
Crystallography
Volume C
Mathematical, physical and chemical tables
Edited by E. Prince

International Tables for Crystallography (2006). Vol. C, ch. 7.4, p. 662

Figure 7.4.4.1 

P. Suorttic
[Figure 7.4.4.1]
Figure 7.4.4.1

Equatorial phase-space diagrams for a conventional X-ray source and parallel-beam geometry; x is the size and x′ = dx/dz the divergence of the X-rays. (a) Radiation distributions for two wavelengths, λ1 and λ2, at the source of width Δx, and downstream at a slit of width ±s1. (b) Acceptance and emittance windows of a flat perfect crystal, where the phase-space volume remains constant, AwaΔλ = EweΔλ, and the (x′, λ) section shows the reflection of a polychromatic beam (Laue diffraction). (c) Distributions for one wavelength at the source, flat perfect-crystal monochromator, sample (marked with the broken line), and the receiving slit (RS); z is the distance from the source.