Angular vibrations of cryogenically cooled double-crystal monochromators

• Published in: Journal of synchrotron radiation Vol. 23; no. 5; pp. 1097 - 1103
• Main Authors: Sergueev, I., Döhrmann, R., Horbach, J., Heuer, J.
• Format: Journal Article
• Language: English
• Published: 5 Abbey Square, Chester, Cheshire CH1 2HU, England International Union of Crystallography 01-09-2016
• Subjects: compound refractive lens; monochromator; X-ray optics; compound refractive lens; monochromator; X-ray optics
• ISSN: 1600-5775; 1600-5775
• DOI: 10.1107/S1600577516011188

The effect of angular vibrations of the crystals in cryogenically cooled monochromators on the beam performance has been studied theoretically and experimentally. A simple relation between amplitude of the vibrations and size of the focused beam is developed. It is shown that the double‐crystal monochromator vibrations affect not only the image size but also the image position along the optical axis. Several methods to measure vibrations with the X‐ray beam are explained and analyzed. The methods have been applied to systematically study angular crystal vibrations at monochromators installed at the PETRA III light source. Characteristic values of the amplitudes of angular vibrations for different monochromators are presented.
A theoretical and experimental investigation of the effect of angular vibrations of a double‐crystal monochromator on the X‐ray beam quality is presented.