P477 – Mirror Unit NIM MLS PTB
Application
Mirror unit for VUV radiation
Year of delivery
2020
Installation site
NIM beamline at Metrology Light Source, National Metrology Institute (PTB), Germany
Design Features
-
Constant-strut-length hexapod mechanism.
- Six degrees of freedom and selectable rotation center.
- Spectral range: 3 – 30 eV.
- Optical elements: one refocusing mirror.
- Mechanically decoupled internal mechanics from the vacuum chamber.
- Internal mechanics directly connected to the adjustable support structure underneath.
-
EtherCAT based motion control system, synchronized encoder readout (suitable for on-the-fly measurements), software with server-client architecture, TCP-IP protocol, EPICS interface.
- Adjustable support structure.
- Permanently installed bakeout provisions.
Performance Features
- High positioning resolution (minimum incremental motion).
- High stability and repeatability for all degrees of freedom.
- 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
1630.30 mm
Number of mirrors
1
Surface shape
ellipsoidal
Mirror dimensions
600 x 120 x 60 mm3
Actuator drives for hexapod axes
Resolution (design value)
0.004 µm /motor fine step
(1/128, recommended)
0.005 µrad /encoder count
Mirror mechanics
Pitch rotation
Range
± 2°
Resolution (measured value)
1 µrad
Repeatability
0.16 µrad (pitch)
0.25 µrad (yaw)
Long-term stability (1h)
0.076 µrad
Roll rotation
Range
± 2°
Resolution (calculated value)
< 1 µrad
Yaw rotation
Range
± 2°
Resolution (measured value)
1 µrad
Repeatability
0.28 µrad (pitch)
0.18 µrad (yaw)
Long-term stability (1h)
0.053 µrad
Vertical translation
Range
± 5 mm
Resolution (calculated value)
< 0.10 µm
Horizontal translations
Range
± 5 mm
Resolution (calculated value)
< 0.10 µm
Performance Test Results
Pitch deviation after pitch change
Yaw deviation after pitch change
Pitch deviation after yaw change
Yaw deviation after yaw change
Mirror pitch positioning resolution
Mirror pitch stability (autocollimator measurement)
Mirror yaw positioning resolution
Mirror yaw stability (autocollimator measurement)
Mirror yaw positioning resolution
(auxiliary encoder, 1 nm resolution)
Residual gas analysis
