Multilayer optics for a wiggler beamline (invited) Available to Purchase

A double crystal, multilayer monochromator was designed and fabricated for a wiggler beamline at the Cornell High Energy Synchrotron Source. The monochromator consists of an internally water-cooled first substrate and a fixed-radius sagittally focusing second substrate, each coated with a multilayer consisting of 100 bilayers of tungsten/carbon with a 27 Å d spacing. Cooled silicon substrates were fabricated with internal water cooling channels to reduce or eliminate thermal distortion. The wide energy bandpass of this multilayer along with sagittal focusing provides the best available flux for time resolved experiments. A flux 100 times that of conventional silicon monochromators is possible and allows for a finer time resolution for the crystal growth studies on this beamline. Measured reflectivities over 60% and bandwidths of 1.3%–1.8% were obtained. Results to beam currents of 350 mA show the effectiveness of the internal cooling design and have provided x-ray fluxes of $8×1013$ photons/s/mm².