P508 – Exit Slit Unit LB ELISA BESSY HZB
Application
Exit slit unit for soft X-ray synchrotron radiation
Year of delivery
2024
Installation site
ELISA beamline (Low Branch) at BESSY II, Helmholtz-Zentrum Berlin, Germany
Design Features
- Double slit mechanism – vertically and horizontally defining slits.
-
Motorized and encoded slits opening, symmetric opening, non-linear opening characteristics.
- Hardened stainless steel slit blades.
- Electrical isolation and fluorescence coating of horizontally defining slit blades.
-
Motorized and encoded translation of the horizontally defining slit transversal to the beam axis.
- Manual rotation of the vertically defining slit mechanism around the beam axis.
- Motorized and encoded slit unit translation along beam axis.
-
Manual slit unit vertical translation.
- 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 0.3 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
Translation along beam axis
Range
-200 mm to 200 mm
Resolution (design value)
0.039 µm /motor fine step
(1/64, recommended)
0.05 µm /encoder count
Resolution (measured value)
0.50 µm
Vertical translation (manual)
Range
± 3.5 mm
Resolution (design value)
0.66 µm /°
Horizontally defining slit (HDS)
Slit blades
Material
hardened stainless steel,
coated with fluorescence material
Straightness
< 0.30 µm over 10 mm (1σ)
Parallelism
-0.05 µm /mm
(40 µm slit opening)
0.04 µm /mm
(150 µm slit opening)
Slit opening
Range
2.10 µm to 6.10 mm
Repeatability
0.06 µm at 20 µm slit opening
0.08 µm at 100 µm slit opening
0.06 µm at 150 µm slit opening
Resolution (design value)
0.00156 µm /motor fine step
(1/64, recommended)
0.05 µm /encoder count
Resolution (measured value)
0.01 µm
Slit translation
Range
-5 mm to 5 mm
Resolution (design value)
0.00156 µm /motor fine step
(1/64, recommended)
0.05 µm /encoder count
Resolution (measured value)
0.05 µm
Vertically defining slit (VDS)
Slit blades
Material
hardened stainless steel
Straightness
< 0.20 µm over 10 mm (1σ)
Parallelism
0.02 µm /mm
(50 µm slit opening)
0.02 µm /mm
(150 µm slit opening)
Slit opening
Range
1.50 µm to 7.70 mm
Repeatability
0.03 µm at 20 µm slit opening
0.08 µm at 100 µm slit opening
0.03 µm at 150 µm slit opening
Resolution (design value)
0.00156 µm /motor fine step
(1/64, recommended)
0.05 µm /encoder count
Resolution (measured value)
0.01 µm
Slit rotation (manual)
Range
± 1°
Performance Test Results
Slit width calibration (HDS)
Slit opening repeatability (HDS)
Slit blades parallelism (HDS)
Slit blades parallelism (HDS)
Slit opening positioning resolution (HDS)
Slit opening positioning resolution (HDS)
Slit translation positioning resolution (HDS)
Slit translation positioning resolution (HDS)
Slit translation positioning resolution (HDS)
Slit width calibration (VDS)
Slit opening repeatability (VDS)
Slit blades parallelism (VDS)
Slit blades parallelism (VDS)
Slit opening positioning resolution (VDS)
Slit opening positioning resolution (VDS)
Slit unit translation positioning resolution
Slit unit translation positioning resolution
Residual gas analysis
