Supply of a horizontally focusing (face side) plane-elliptical X-ray mirror for beamline P22 at PETRA III
X-rays emitted from an undulator device at the PETRA III light source of DESY are mono-chromatized and then focused vertically and horizontally at the position of an experimental chamber far away from the source.
The horizontal focusing of the monochromatic beam is done by a long X-ray mirror (face side, 950 mm optical length) of plane-elliptical shape, the glancing angle of incidence is around 3 m rad. The mirror center is located 79.5 m from the source and installed on the floor of an experimental shielding hutch, the focal distance varies from 2.0 to 6.0 m from the mirror center, i.e. the demagnification ratio ranges from about 40 to 13. The varying focal distance requires a corresponding continuous and precise adjustment of the ellipse parameters by means of a suitable mirror bending mechanism.
The mirror system is integrated into the UHV environment of the beam path and has to comply with DESY's vacuum specifications, its geometry and support structure is adapted for integration into the existing beamline.