P435 – Mirror Unit SXR XFEL PAL
Application
Mirror unit (M1) for soft X-ray synchrotron radiation
Year of delivery
2016
Installation site
Soft X-ray beamline (XFEL) at Pohang Accelerator Laboratory, South Korea
This mirror unit for the soft X-ray beamline at the Korean XFEL features a cardanic mount to realize the required degrees of freedom. B4C beam blocking provisions are integrated in the system.
Design Features
-
In-UHV stacked design for the requested degrees of freedom.
-
XFEL compatible.
- Spectral range: 270 – 1300 eV.
- Pitch rotation stage motorized and encoded in-UHV.
- Roll rotation guidance system motorized and encoded in-UHV.
- Linear stage for mirror horizontal translation motorized and encoded in-air.
- Temperature sensor at pitch stage.
- Electrode at mirror surface for carbon contamination prevention.
- Active water cooling of the mirror.
-
Motion control system with EPICS interface.
- Adjustable support structure.
- Permanently installed bakeout provisions.
Performance Features
- High positioning resolution (minimum incremental motion).
- High pitch rotation stability and repeatability.
- Minimized mounting induced deformations.
Outer Dimensions
Technical specifications and performance values
General
Vacuum chamber
Chamber type
cylindrical, vertical axis
Main flanges
at the top
Material
1.4404 (C < 0.02%)
Base pressure
10-10 mbar range
Optical design parameters
Beam height
1400 mm
Number of mirrors
1
Surface shape
plane
Mirror dimensions
600 mm x 50 mm x 50 mm
Mirror mechanics
Pitch rotation
Range
± 5 mrad
Resolution (design value)
0.036 µrad /motor step
0.0067 µrad /encoder count
Resolution (measured value)
0.05 µrad
Repeatability
0.11 µrad (pitch)
0.15 µrad (roll)
Long-term stability (> 30 minutes)
0.016 µrad
Roll rotation
Range
± 10 mrad
Resolution (design value)
0.068 µrad /motor step
0.0067 µrad /encoder count
Resolution (measured value)
0.10 µrad
Repeatability
0.05 µrad (pitch)
0.16 µrad (roll)
Long-term stability (> 30 minutes)
0.023 µrad
Translation
along surface normal
Range
± 10 mm
Resolution
0.30 µm /motor step
0.05 µm /encoder count
Repeatability
0.06 µrad (pitch)
0.13 µrad (roll)
Performance Test Results
Pitch deviation after pitch change
Roll deviation after pitch change
Pitch deviation after roll change
Roll deviation after roll change
Pitch deviation after mirror translation
Roll deviation after mirror translation
Mirror pitch positioning resolution
Mirror pitch long-term stability
Mirror roll positioning resolution
Mirror roll long-term stability
Residual gas analysis
