Observation of Interference Effects at the Focus of an X-ray Lens.
During an experiment on synchrotron radiation focusing with a capillary lens, an interference structure was observed at the focal spot of the lens, despite the fact that the lens capillary diameter is about a million times greater than the wavelength of the X-ray photons (600 mum and 8 A, respectively). The width of the central peak is close to the capillary diameter. At the same time the synchrotron radiation concentration increased by more than one hundred times. Analysis shows that the capillary lens acts in many respects as a macroscopic crystal. The observed effect is accounted for by wave theory. This phenomenon may have important practical effects in many fields.