LS-CAT

JJ X-Ray has provided two Laue Diamond Monochromator stations to LS-CAT (21-ID) at APS, Argonne National Laboratory, USA.

We delivered two side branch stations at LS-CAT comprised by two Diamond Laue monochromators as beam splitters and beryllium lenses for focusing the beam onto the sample.

There are two identical systems operating at the selenium edge (12.668 keV) using the same part of the synchrotron radiation beam.

The two beamlines are based on a (100)-normal diamond crystal  using the (111) Bragg reflection followed by 6-7 parabolic beryllium lenses providing a focused beam of 50µm x 70µm with 1x1012 ph/s and a resolution of 2x10-4 at a position 10 m downstream of the monochromator diamond crystal.

The diamond crystals can be positioned with four degrees of freedom (theta, chi, z and y). The two rotations are in-vacuum piezo motors, and the two translations are external motions. The stability of the monochromator is essential, and vibrational FEA has been used to avoid resonance frequencies overlapping with the frequency spectrum present in the experimental hall.

The diffracted beam is guided with the aid of a beam viewer (YAG crystal) to the focusing beryllium lenses. These are also equipped with four degrees of freedom (pitch, yaw, z and y) and can be aligned with the beam. The focused beam is delivered with 10 m downstream.