P433 – Exit Slit Unit SXR XFEL PAL
Application
Exit slit unit for soft X-ray FEL radiation
Year of delivery
2016
Installation site
Soft X-ray beamline (XFEL) at Pohang Accelerator Laboratory, South Korea
Design Features
-
Vertically defining slit with motorized and encoded slit opening.
-
Symmetric slit opening, non-linear opening characteristics.
- B4C slit blades.
-
Motion control system with EPICS interface.
- Adjustable support structure.
Performance Features
- Precision and slit opening repeatability smaller than 100 nm.
- Parallelism smaller than 0.5 µm over 10 mm edge length.
- Straightness smaller than 1 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
B4C
Straightness
0.80 µm over 10 mm (1σ)
Parallelism
-0.03 µm /mm
(140 µm slit opening)
Slit opening
Range
0 µm to 8 mm
Repeatability
± 0.07 µm
(up to 140 µm slit opening)
Resolution (design value)
0.006 µm /motor fine step
(1/16, recommended)
0.05 µm /encoder count
Performance Test Results
Slit width calibration (VDS)
Slit opening repeatability (VDS)
Slit blades parallelism (VDS)
