Beamline Specifications and Schematic

There are many possible types of scans available on I20-Scanning. Typical scan times are as follows:

Vertical collimating mirror:

The first optical element is an upwards deflecting vertical collimating mirror (Rh and Pt stripes). Given the large divergence of the wiggler source, a collimating mirror is essential to maximised the flux through the monochromator.

Vertical deflecting mirror:

This is a downwards deflecting flat mirror (Rh and Pt stripes). First, it will restore the horizontal trajectory of the beam before enters the monochromator and, second, will decouple any adjustment of the angle of the first mirror from the monochromator.

Four bounce crystal monochromator:

The monochromator is unique and consists of two pairs of counter-rotating crystals. It has been designed in-house at Diamond. The advantages are: a) high stability and reproducibility, b) fixed exit by geometry, c) angle and energy resolution of transmitted photons are not determined by the incident beam divergence.

Horizontal focusing mirror:

This is a long sagittal focusing cylinder (Rh and Pt cylinders).

Vertical focusing mirror:

This flat mirror is installed in a bender and is mechanically deformed to focus the beam in the tangential direction (Rh and Pt stripes).

Harmonic rejection mirrors: 

The requirement of a high spectral purity of the X-ray beam to be delivered to the sample makes it essenstial to reduce the harmonic content of the beam (Rh and Si stripes, angular range from 3 to 5 mrad).