P398 – Exit Slit Unit I21-IXS DLS
Application
Exit slit unit for soft X-ray synchrotron radiation
Year of delivery
2015
Installation site
Beamline I21-IXS at Diamond Light Source, Didcot, United Kingdom
Design Features
-
Three independent slit opening mechanisms – two vertically and one horizontally defining slits.
-
Motorized and encoded slits opening, symmetric opening, non-linear opening characteristics.
- Tungsten slit blades.
- Motorized and encoded slit unit translation along beam axis.
- Metal plate with adjustable YAG screen.
- 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
± 250 mm
Resolution (design value)
0.015 µm /motor fine step
(1/64, recommended)
0.05 µm /encoder count
Chamber roll
± 25 µrad
(over 500 mm translation)
Horizontally defining slit (HDS)
Slit blades
Material
Tungsten
Straightness
< 0.10 µm over 10 mm (1σ)
Parallelism
-0.07 µm /mm
(10 µm slit opening)
-0.05 µm /mm
(25 µm slit opening)
-0.01 µm /mm
(50 µm slit opening)
Slit opening
Range
0.6 µm to 10 mm
Repeatability
± 0.20 µm
(up to 400 µm slit opening)
Resolution (design value)
0.006 µm /motor fine step
(1/16, recommended)
0.05 µm /encoder count
Vertically defining slit (VDS 1)
Slit blades
Material
Tungsten
Straightness
< 0.30 µm over 10 mm (1σ)
Parallelism
-0.009 µm /mm
(10 µm slit opening)
-0.004 µm /mm
(25 µm slit opening)
-0.04 µm /mm
(50 µm slit opening)
Slit opening
Range
3 µm to 10 mm
Repeatability
± 0.33 µm
(up to 400 µm slit opening)
Resolution (design value)
0.006 µm /motor fine step
(1/16, recommended)
0.05 µm /encoder count
Vertically defining slit (VDS 2)
Slit blades
Material
Tungsten
Straightness
< 0.20 µm over 10 mm (1σ)
Parallelism
-0.04 µm /mm
(10 µm slit opening)
-0.02 µm /mm
(25 µm slit opening)
-0.03 µm /mm
(50 µm slit opening)
Slit opening
Range
3 µm to 10 mm
Repeatability
± 0.28 µm
(up to 430 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 blades parallelism (HDS)
Slit blades parallelism (HDS)
Slit width calibration (VDS 1)
Slit opening repeatability (VDS 1)
Slit blades parallelism (VDS 1)
Slit blades parallelism (VDS 1)
Slit blades parallelism (VDS 1)
Slit width calibration (VDS 2)
Slit opening repeatability (VDS 2)
Slit blades parallelism (VDS 2)
Slit blades parallelism (VDS 2)
Slit blades parallelism (VDS 2)
Residual gas analysis
