Diffraction of X-ray beams in capillary waveguides

Propagation of the soft X-ray radiation generated by a small-diameter incoh erent source through the capillary plane waveguide which satisfies the mult imode condition is studied using the Fresnel-Kirchhoff diffraction theory. The diffraction is manifested by appearance of the diffraction fringes, dar k and light bands, in the far-field zone of the capillary output. Such a be haviour of the X-ray radiation is confirmed by our experimental data. The r esults give explanation for the interference effect recently observed in ma ny experiments on the grazing reflections of X-rays in single and multiple capillary optics. (C) 2000 Elsevier Science B.V. All rights reserved.