Article Metrics


Online attention

Compensation of x-ray mirror distortion by cooling temperature control

DOI: 10.1063/1.5084675 DOI Help

Authors: Matthew Hand (Diamond Light Source) , Hongchang Wang (Diamond Light Source) , Maria Harkiolaki (Diamond Light Source) , Federica Venturini (Diamond Light Source) , Rosa Arrigo (Diamond Light Source Ltd.) , Pilar Ferrer Escorihuela (Diamond Light Source) , Simon Alcock (Diamond Light Source) , Ioana Nistea (Diamond Light Source) , Andy Marshall (Diamond Light Source) , Stewart Scott (Diamond Light Source) , Liz Duke (Diamond Light Source) , Georg Held (Diamond Light Source) , Kawal Sawhney (Diamond Light Source)
Co-authored by industrial partner: No

Type: Conference Paper
Conference: Proceedings of the 13th International Conference on Synchrotron Radiation Instrumentation – SRI2018
Peer Reviewed: No

State: Published (Approved)
Published: January 2019

Open Access Open Access

Abstract: Synchrotron radiation is emitted from a bending magnet source in a wide ray fan which is collected by the first optical element in a beamline. In order to maximize angular acceptance, and hence flux, it is beneficial to increase the length of this mirror and optical design requirements may necessitate that the optical surface be over 1 m in length. Such mirrors also require cooling as they may be subject to high heat loads from the incident radiation. Two beamlines, B07 and B24, at Diamond Light Source, UK, use 1.4 m long toroidal mirrors which utilize a similar side-clamped cooling manifold design. While this scheme has been successful in providing effective cooling of the mirror, it has also been discovered that it introduces deformation of the radius of curvature which is sufficient to alter the focusing characteristics of the mirror. At both beamlines, the horizontal focus of the beam was found to differ by up to several meter from the design position at the exit slit which resulted in poor flux throughput, reduced energy resolution and other side effects. A pencil beam scan method has been used to diagnose this issue and infer the position of the focus and mirror shape. Through the use of a standalone chiller to alter the temperature of the water within the cooling loop, it has been possible to correct the distortion of the radius and restore the focus to its nominal position.

Journal Keywords: Synchrotron radiation; Optical elements; X-ray mirrors

Subject Areas: Technique Development

Technical Areas: Optics