Abstract
Side-bounce beamlines with fixed-exit angles have been intended to operate with only one selected energy. However, a tunable monochromator in a new geometry is presented here that will make side-bounce beamlines energy tunable. It requires the addition of two more rotations. Analytic solutions for the values of these two rotation angles are provided. The validity of the new concept was checked by ray tracing and two-dimensional searches in the additional angles. Operational details on the new scheme, including the exit offset and steering of the beams, were determined. In addition to tunability, the new monochromator will reduce the loss from the polarization factor at low energies.
Highlights
Double-crystal monochromators (DCMs) are used for most of the hard X-ray beamlines at synchrotron radiation facilities (Mills & King, 1983; Golovchenko et al, 1981)
The single-bounce monochromator usually has a fixed-exit angle, and the available energy is determined by the diffracting crystal and the exit angle
On a side-bounce beamline designed for 15 keV, a twisted DCM can provide photons up to 29.85 keV
Summary
Double-crystal monochromators (DCMs) are used for most of the hard X-ray beamlines at synchrotron radiation facilities (Mills & King, 1983; Golovchenko et al, 1981). The single-bounce monochromator usually has a fixed-exit angle, and the available energy is determined by the diffracting crystal and the exit angle. When one steers an X-ray beam with a monochromator, the steering must hold the Bragg condition between the incoming ray and the diffracting crystal. A rotation of the crystal about a vector normal to the diffraction plane will preserve the Bragg condition. Rotating about the incoming ray will rotate the outgoing ray while preserving the Bragg condition. This is similar to steering the outgoing beam with a ‘chi motion’. Are the steps taken when one steers a beam of a particular photon energy to a fixed-exit angle, using two new rotations on two crystals. Rotate (3) Choose and to match the exit angle to the the whole DCM counter-clockwise (watching from upstream) desired one
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: 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.
