P491 – Exit Slit Unit FURKA SwissFEL PSI
Application
Exit slit unit for soft X-ray radiation
Year of delivery
2021
Installation site
ATHOS beamline at Swiss FEL, Paul Scherrer Institut, Switzerland
Design Features
-
Vertically defining slit with motorized and encoded slit opening.
-
Symmetric slit opening, non-linear opening characteristics.
- Hardened stainless steel slit blades.
- Motorized and encoded manipulator (horizontal/vertical direction) with holder for scintillator screens.
- Adjustable support structure.
Performance Features
- Precision and slit opening repeatability smaller than 150 nm.
- Parallelism smaller than 0.5 µm over 10 mm edge length.
- Straightness smaller than 0.2 µm over 10 mm edge length.
- Very small deviation (submicrometer) of the slit opening calibration curve from the theoretical non-linear slit opening function.
Outer Dimensions
Technical specifications and performance values
General
Vacuum chamber
Chamber type
cylindrical, horizontal axis
Main flanges
DN160CF cluster flanges
Material
1.4301
Base pressure
10-10 mbar range
Vertically defining slit (VDS)
Slit blades
Material
hardened stainless steel
Straightness
< 0.70 µm over 38 mm (1σ)
Parallelism
0.04 µm /mm
(ca. 56 µm slit opening)
Slit opening
Range
3 µm to 9.2 mm
Repeatability
0.11 µm at 19 µm slit opening
0.05 µm at 45 µm slit opening
0.05 µm at 175 µm slit opening
Resolution (design value)
0.00156 µm /motor fine step
(1/64, recommended)
0.05 µm /encoder count
Manipulator for scintillator screens
Horizontal translation
Range
-11.80 mm to 11.84 mm
Resolution (design value)
0.23 µm /motor fine step
(1/64, recommended)
0.05 µm /encoder count
Resolution (measured value)
5 µm
Repeatability
0.70 µm (translation)
Vertical translation
Range
-50.35 mm 50 mm
Resolution (design value)
0.23 µm /motor fine step
(1/64, recommended)
0.05 µm /encoder count
Resolution (measured value)
5 µm
Repeatability
1.35 µm (translation)
Performance Test Results
Slit width calibration (VDS)
Slit opening repeatability (VDS)
Slit blades parallelism (VDS)
Manipulator horizontal deviation after translation
Manipulator horizontal positioning resolution
Manipulator vertical deviation after translation
Manipulator vertical positioning resolution
Residual gas analysis
