P309 – Exit Slit Unit SXR LCLS SLAC
Application
Exit slit unit for soft X-ray FEL radiation
Year of delivery
2010
Installation site
Soft X-ray beamline at LCLS, Stanford Linear accelerator Center, USA
Design Features
-
Vertically defining slit with motorized and encoded slit opening.
- Symmetric opening, non-linear opening characteristics.
-
B4C slit blades.
- Adjustable support structure.
Performance Features
- Precision and slit opening repeatability smaller than 100 nm.
- Parallelism smaller than 4 µm over 10 mm edge length.
- Straightness smaller than 0.6 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
< 0.60 µm over 10 mm (1σ)
Parallelism
0.37 µm /mm (85 µm slit opening)
Slit opening
Range
0 µm to 10 mm
Repeatability
± 0.043 µm up to 350 µm slit opening
Resolution (design value)
0.04 µm /motor fine step
(1/128, recommended)
0.05 µm /encoer count
Performance Test Results
Slit width calibration (VDS)
Slit opening repeatability (VDS)
Slit blade parallelism (VDS)
