X-ray dynamical diffraction in Ge with a zero-real-part scattering factor

X-ray dynamical diffraction induced only by the imaginary part of the scattering factor was measured using a Ge perfect crystal. The 844 integrated reflecting intensities near the K-absorption edge were measured in both the Bragg and the Laue cases. The intensities show the characteristic variations for the scattering factor having no real part, which agree well with theoretical predictions. There remains a slight difference between the theoretical [Fukamachi & Kawamura (1993). Acta Cryst. A49, 384-388] and the experimental energy position at which this occurs, which is related to the fine structure of the anomalous scattering factor above the absorption edge.