Wave optics treatment of x‐rays passing through tapered capillary guides

The propagation of soft X-rays generated by a small-diameter incoherent source through a tapered, plane capillary-type waveguide was studied using the Fresnel-Kirchhoff theory and method of images. The diffraction and interference are manifested by the appearance of the diffraction fringes in both the near- and far-field zones of the waveguide output. The experimental data confirm such behaviour of the X-radiation.