9. Primary and secondary extinctions

So far, we have only considered absorption as a phenomenon that weakens the intensity of the incident X-ray beam penetrating a solid. Any point on the crystal can in fact be in the path of an incident i ₂ ray and an i ₁ ray diffracted at A (figure 13 ). The ray $i_1^{\prime }$ diffracts at B on a plane parallel to the diffraction plane passing through A, becoming $i_1^{″}$ . This double diffraction makes $i_1^{″}$...