P383 – Exit Slit Unit B24 DLS
Application
Exit slit unit for soft X-ray synchrotron radiation
Year of delivery
2014
Installation site
Beamline B24 at Diamond Light Source, Didcot, United Kingdom
This exit slit unit is the first featuring a modified design of the slit blade mechanics for improved alignment stability. A customized wedge leveler was used for a more convenient and reliable height adjustment of the slit unit.
Design Features
-
Double slit mechanism – vertically and horizontally defining slits.
- Motorized and encoded slits opening, symmetric opening, non-linear opening characteristics.
- Tungsten slit blades.
-
Electrical isolation of all slit blades.
- Motorized and encoded slit unit translation along beam axis.
- Bias plate with adjustable YAG screen.
- Manually adjustable wedge leveler.
- Adjustable support structure.
Performance Features
- Precision and slit opening repeatability smaller than 100 nm.
- Parallelism smaller than 0.8 µm over 10 mm edge length.
- Straightness smaller than 0.5 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
± 100 mm
Resolution (design value)
0.015 µm /motor fine step
(1/128, recommended)
0.05 µm /encoder count
Support structure
adjustment ranges
Height
± 10 mm
Lateral
± 10 mm
Longitudinal
± 10 mm
Horizontally defining slit (HDS)
Slit blades
Material
Tungsten
Straightness
0.42 µm over 12 mm (1σ)
Parallelism
0.04 µm /mm (65 µm slit opening)
Slit opening
Range
0 µm to 8 mm
Repeatability
± 0.06 µm
(up to 50 µm slit opening)
Resolution (design value)
0.006 µm /motor fine step
(1/16, recommended)
0.05 µm /encoder count
Vertically defining slit (VDS)
Slit blades
Material
Tungsten
Straightness
< 0.40 µm over 20 mm (1σ)
Parallelism
-0.07 µm /mm
(10 µm slit opening)
-0.05 µm /mm
(25 µm slit opening)
-0.03 µm /mm
(50 µm slit opening)
Slit opening
Range
3.7 µm to 8 mm
Repeatability
± 0.05 µm
(up to 350 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 (HDS)
Slit opening repeatability (HDS)
Slit blades parallelism (HDS)
Slit width calibration (VDS)
Slit opening repeatability (VDS)
Slit blades parallelism (VDS)
Slit blades parallelism (VDS)
Slit blades parallelism (VDS)
Residual gas analysis
