Diffraction of x rays in capillary optics

Propagation of x rays generated by a small-diameter incoherent source throu gh the capillary waveguide that satisfies the multimode condition is studie d with the Fresnel-Kirchhoff diffraction theory. The strong influence of di ffraction on the propagation is demonstrated The diffraction phenomenon is manifested by the appearance of diffraction fringes in both the guide chann el and the far-field zone of the capillary output. Experimental data that c onfirm such behavior of the x-ray radiation is also presented. The results confirm the interference effects recently observed in some experiments on t he grazing reflections of x rays in single- and multiple-capillary optics. (C) 2000 Optical Society of America.