X-ray Optics Group
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The mission of the ESRF Optics Group is to:
- manufacture and characterise optical elements
- conduct research and development of X-ray optical elements in general
- assist at the conception, construction and improvement of the ESRF beamlines
Activities and staff (about 10) are divided into three domains:
Preparation of single crystal monochromators
The crystal laboratory is in charge of manufacturing 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 up to 300 mm long pieces.
Requests for such in-house projects can be made via the form on our intranet site (onsite only, login required). External laboratories should contact the Optics Group staff for their requests.
Mirror surface quality evaluation and bending techniques
Our mirror metrology laboratory in a clean room comprises a long trace profiler for slope error measurements (10 nano-radian resolution) of up to 1.8 m long mirrors, a microroughness interferometer (0.05 nm resolution) and a Fizeau interferometer for shape measurements of up to 150 mm long specimen. 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 15cm wide. The range of energy resolution, traditionally 1 to 10% has recently been extended from 0.25% to 20%.
Prof. John Rehr: seminar and practical on FEFF9