MEDSI2025 - 13th International Conference on Mechanical Engineering Design of Synchrotron Radiation Equipment and Instrumentation

Mechanical design of an off-axis parabolic mirror holder with six degrees of freedom

TUP42

16 Sept 2025, 17:00

1h 15m

Poster Session Room (The Loop)

Poster Presentation Beamlines and Instruments Poster Session 1

Speaker

Alexander Reich (European X-Ray Free-Electron Laser)

Description

The XRD (X-Ray Diffraction Chamber) is one of the endstations of the SCS instrument, specifically designed for experiments on solid targets. Its sample holder features six-degree-of-freedom motion, allowing for precise positioning and alignment of the sample. During THz experiments at the XRD endstation of the SCS instrument, a 2″ off-axis parabolic mirror must be precisely positioned in six degrees of freedom under UHV conditions (10⁻⁷ mbar). Each axis is equipped with encoder feedback and adjustable limit switches. Because of the focus length of 50.8 mm (2 ”) there is a very limited installation space. In operation, the mirror is translated and rotated into the X-ray beam path so that the THz and X-ray beams overlap exactly at the sample. After the measurement, the mirror has to be fully retracted from the beam path. The design challenge is to create a support system that is statically over-determined for rigidity. The system can be temporarily decoupled to form an under-determined mechanism for pre-alignment.