SEARCH Articles Figures Tables Darwin Diffraction of X-rays Diffraction optical Diffraction theory Diffractive optics Dynamical analogy Dynamical diffraction Dynamical theory Dynamics, theory For X-rays Optic axis Optical axis Optical propagation Pitch Pitching Propagation dynamics Ray optics Ray theory The Analogy The propagators Wavelength X-ray X-axis X-propagator X-rays optics