Journal of Synchrotron Radiation

Volume 13, Part 1 (January 2006)

research papers

J. Synchrotron Rad. (2006). 13, 54-58 [ doi:10.1107/S0909049505036903 ]

A wide-aperture dynamically focusing sagittal monochromator for X-ray spectroscopy and diffraction

R. L. Bilsborrow, P. A. Atkinson, N. Bliss, A. J. Dent, B. R. Dobson and P. C. Stephenson

Abstract: A scanning dynamically focusing sagittal X-ray monochromator accepting 7 mrad of the fan from a 6 T wiggler is in routine use on beamline 16.5 (ultra-dilute spectroscopy) of the SRS at CCLRC Daresbury Laboratory, UK. The energy range covered is 7-27 keV, with a horizontal spot size of <1.1 mm FWHM. Measured monochromatic flux from a Si 220 crystal pair is 1 × 10¹¹ photons s^-1 (100 mA)^-1 at 9 keV. This level of flux, usually associated with an insertion device on a third-generation source, permits collection of EXAFS data on concentrations at or below 10 ppm.

Keywords: X-ray monochromator; wide aperture; sagittal focus; dynamic focus; X-ray spectroscopy.