The X-ray Optics Group performs research and development of X-ray optical elements and systems, provides assistance to ESRF and Collaborating Research Group (CRG) scientists and engineers in the conception of the beamlines by designing, fabricating and testing optical elements. The group comprises three teams that operate the
- Provide advice, support, facilities, development and measurement capabilities relating to X-ray Optics for Experiments Division, Accelerator and Source Division, CRGs and internally within ISDD.
- Act, when required, as Coordinator with other support services (Mechanical Engineering Group, Computing Services and Technical Services) for interventions on ESRF beamlines.
- Initiate research and development of new X-ray optical elements and systems.
Preparation of single crystal monochromators
The crystal laboratory manufactures monochromators and other crystal-based optics. Its activities include orienting, cutting, grinding and polishing of crystals, mainly silicon, starting with float zone material of the highest available quality. Presently, even mirror quality figure and finish (1 µ-radian slope error and 0.1 nm roughness, rms) can be obtained by strain-free, mechano-chemical polishing of pieces up to 300 mm long.
Requests for such projects from in-house groups can be made via the form on our intranet site (onsite only, login required). External laboratories should write to the Optics Group staff to discuss their needs.
Mirror surface quality evaluation and bending techniques
Our mirror and metrology laboratory in a clean room comprises a long trace profiler for slope error measurements (10 nano-radian resolution) of mirrors up to 1.8 m long, a microroughness interferometer (0.05 nm resolution) and a Fizeau interferometer for shape measurements of specimens up to 150 mm long. An atomic force microscope completes the instrumentation. Very precise mechanical benders are assembled to build Kirkpatrick-Baez focusing systems.
Deposition of multilayer interference mirrors
The multilayer laboratory operates a sputter deposition machine and an X-ray reflectometer for performance evaluation. Laterally (for monochromatic focusing) and in-depth graded (for broadband applications) devices are produced using super-polished, mainly silicon substrates, up to 1 m long and 15 cm wide. The range of energy resolution, traditionally 1 to 10%, has recently been extended from 0.25% to 20%.