P518 – Exit Slit Unit DIAVOLEZZA SwissFEL PSI
Application
Exit slit unit for soft X-ray radiation
Year of delivery
2025
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.
- OFHC 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 15 mm edge length.
- Straightness smaller than 0.2 µm over 15 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
Vertically defining slit (VDS)
Slit blades
Material
OFHC
Straightness
< 0.20 µm over 15 mm (1σ)
Parallelism
0.02 μm /mm
(at ca. 50 μm slit opening)
-0.01 μm /mm
(at ca. 100 μm slit opening)
0.03 μm /mm
(at ca. 200 μm slit opening)
Slit opening
Range
4.6 µm to 9.20 mm
(+4 mm at the notch)
Repeatability
< 0.10 µm
(for slit apertures < 300 µm)
< 0.15 µm
(for slit apertures > 300 µm)
Variation of slit center position while opening
< 1 µm
Resolution (design value)
0.00156 µm /motor fine step
(1/64, recommended)
0.05 µm /encoder count
Resolution (measured value)
0.01 µm
Manipulator for scintillator screens
Horizontal translation
Range
-11 mm to 11 mm
Resolution (design value)
0.23 µm /motor fine step
(1/64, recommended)
0.05 µm /encoder count
Resolution (measured value)
0.20 µm
Repeatability
< 0.10 µm (translation)
Vertical translation
Range
-0.15 mm 100.2 mm
Resolution (design value)
0.23 µm /motor fine step
(1/64, recommended)
0.05 µm /encoder count
Resolution (measured value)
0.20 µm
Repeatability
< 0.10 µm (translation)
Performance Test Results
Slit width calibration (VDS)
Variation of slit center position (VDS)
Slit opening repeatability (VDS)
Slit opening repeatability (VDS)
Slit blades parallelism (VDS)
Slit blades parallelism (VDS)
Slit blades parallelism (VDS)
Slit blades parallelism (VDS)
Slit opening positioning resolution (VDS)
Slit opening positioning resolution (VDS)
Slit opening positioning resolution (VDS)
Slit opening positioning resolution (VDS)
Slit opening positioning resolution (VDS)
Slit opening positioning resolution (VDS)
Manipulator horizontal deviation after translation
Manipulator horizontal positioning resolution
Manipulator vertical deviation after translation
Manipulator vertical positioning resolution
Residual gas analysis
