![P441 - Monochromator - Bestec GmbH_05 P441 - Spherical grating monochromator (SGM) for soft X-ray synchrotron radiation at Beamline I21-IXS at Diamond Light Source, Didcot, United Kingdom](https://bestec-optics.com/wp-content/uploads/2016/04/P441-Monochromator-Bestec-GmbH_05-939x1024.png)
P441 – SGM I21-IXS DLS
Application
Spherical grating monochromator (SGM) for soft X-ray synchrotron radiation
Year of delivery
2016
Installation site
Beamline I21-IXS at Diamond Light Source, Didcot, United Kingdom
This grating unit was developed and built to be integrated into the high energy resolution RIXS system at I21-IXS at DLS. The challenge was to accomodate all components for standard functionality and for compensation of spectrometer related spurious movements into a very limited space, without perfomance lost.
Design Features
- Grating unit for high resolution soft X-ray spectrometer.
- Spectral range: 250 – 3000 eV.
-
Very compact design for integration into the RIXS system.
- Optical elements: three spherical gratings.
- Temperature sensors at internal mechanics.
- Motorized and encoded vertical translation of the internal mechanics for compensation of spurios height and roll variation upon scattering angle change.
- Permanently installed bakeout provisions.
- Adjustable support structure.
Performance Features
- High pitch rotation stability and repeatability.
- Minimized mounting induced deformations.
Outer Dimensions
Technical specifications and performance values
General
Vacuum chamber
Chamber type
rectangular footprint
Main flanges
at the top
Material
1.4404 (C < 0.02%)
Base pressure
10-10 mbar range
Optical design parameters
Beam height
1415 mm
Number of gratings
3
Grating dimensions
200 mm x 40 mm x 50 mm
Grating mechanics
Pitch rotation
Range
-10.70° to +1.4°
Resolution
0.004 µrad /motor fine step
(1/64, recommended)
0.0047961 µrad /encoder count
Repeatability
0.08 µrad (pitch)
0.20 µrad (roll)
Stability
0.012 µrad
Translation (grating exchange)
Range
-115.3 mm to +76.3 mm
Resolution (design value)
0.40 µm /motor fine step
(1/128, recommended)
0.05 µm /encoder count
Repeatability
0.20 µrad (pitch)
0.17 µrad (roll)
Translation (grating height)
Range
-1.18 mm to +1.13 mm
(wedge leveler 1)
-1.15 mm to +1.48 mm
(wedge leveler 2)
Resolution (design value)
0.40 µm /motor step (at actuator)
0.02 µm /motor step
(at wedge leveler)
0.005 µm /encoder count