P472 – Exit Slit Unit STXM EMIL BESSY
Application
Exit slit unit for soft X-ray synchrotron radiation
Year of delivery
2019
Installation site
STXM beamline at BESSY, 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.
- OFHC slit blades.
- Electrical isolation 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.
- Isolated bias plate.
- Adjustable support structure.
Performance Features
- Precision and slit opening repeatability smaller than 100 nm.
- Parallelism smaller than 1 µm over 10 mm edge length.
- Straightness smaller than 0.25 µm over 10 mm edgle 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
± 250 mm
Resolution (design value)
0.025 µm /motor fine step
(1/16, recommended)
0.01 µm /encoder count
Horizontally defining slit (HDS)
Slit blades
Material
Hardened stainless steel, gold coated
Straightness
< 0.20 µm over 10 mm (1σ)
Parallelism
-0.03 µm /mm
(20 µm slit opening)
0.01 µm /mm
(50 µm slit opening)
0.003 µm /mm
(100 µm slit opening)
Slit opening
Range
0 µm to 6 mm
Repeatability
± 0.033 µm at 20 µm slit opening
± 0.023 µm at 50 µm slit opening
± 0.009 µm at 100 µm slit opening
Stability (> 30 min)
0.002µm
Resolution (design value)
0.006 µm /motor fine step
(1/16, recommended)
0.01 µm /encoder count
Slit translation
Range
-5.4 mm to 6 mm
Resolution (design value)
0.006 µm /motor fine step
(1/16, recommended)
0.01 µm /encoder count
Vertically defining slit (VDS)
Slit blades
Material
Hardened stainless steel
Straightness
< 0.25 µm over 10 mm (1σ)
Parallelism
-0.07 µm /mm
(20 µm slit opening)
0.06 µm /mm
(50 µm slit opening)
0.002 µm /mm
(up to 100 µm slit opening)
Slit opening
Range
0 µm to 2.3 mm
Repeatability
± 0.011 µm at 10 µm slit opening
± 0.002 µm at 50 µm slit opening
± 0.003 µm at 100 µm slit opening
Long-term stability (> 2 h)
0.004 µm
Resolution (design value)
0.006 µm /motor fine step
(1/16, recommended)
0.01 µm /encoder count
Slit rotation
Range
– 0.5° to 0.5°
Actuator
manual rotary feedthrough
Resolution (design value)
0.153° /turn
Performance Test Results
Slit width calibration (HDS)
Slit opening repeatability (HDS)
Slit blades parallelism (HDS)
Slit blades parallelism (HDS)
Slit blades parallelism (HDS)
Slit opening stability (HDS)
Slit width calibration (VDS)
Slit opening repeatability (VDS)
Slit blades parallelism (VDS)
Slit blades parallelism (VDS)
Slit blades parallelism (VDS)
Slit opening long-term stability (VDS)
