Abstract
A novel method for focusing X-rays in two dimensions by thermal-gradient crystals in symmetrical Laue geometry is described. A 225 kV stationary tungsten tube delivers an X-ray beam with a source diameter of about 1.0 mm (full width at half-maximum). The focal point at the detector at a distance up to 16 m from the source is of the same size. The beam at the focusing crystals at half the distance between the source and the detector has typical dimensions of 30 × 30 mm. The intensity of the focal point can be increased by more than 200 times by applying a thermal gradient of about 2.2 K mm−1on the focusing crystals. The described method and apparatus are designed for small-angle X-ray scattering at high photon energies up to 60 keV, where the high penetration power allows experiments on strongly absorbing materials in transmission mode. Particle sizes up to 3000 Å can be detected. First measurements on nanocrystalline tungsten carbide and Teflon yield radii of gyration of 540 Å and 815 Å, respectively.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.