P492 – PGM SABIA LNLS
Application
Plane grating monochromator (PGM) for soft X-ray synchrotron radiation
Year of delivery
2022
Installation site
SABIA beamline at Sirius Synchrotron Light Source, LNLS Brazil
Design Features
- High-resolution grazing incidence variable line spacing plane grating monochromator (PGM).
- Spectral range: 100 – 2000 eV.
- Optical elements: one plane mirror and four plane gratings.
- Temperature sensors at internal mechanics, mirror and gratings holders.
-
Active water cooling of all optical elements.
- Water cooled zero-order beam stop.
-
Motion control system with EPICS interface, EtherCAT, fast encoder readout suitable for on-the-fly measurements.
- Mechanically decoupled internal mechanics from the vacuum chamber.
- Internal mechanics directly connected to the adjustable support structure underneath.
- Adjustable support structure.
- Permanently installed bakeout provisions.
Performance Features
- High positioning resolution (minimum incremental motion).
- High pitch rotation stability and repeatability.
- Minimized mounting induced deformations.
Outer Dimensions
Technical specifications and performance values
General
Vacuum chamber
Chamber type
cylindrical, vertical axis
Main flanges
at the top
Material
1.4404 (C < 0.02%)
Base pressure
10-10 mbar range
Optical design parameters
Beam height (entrance)
1390 mm
Beam offset
18 mm
Number of plane mirrors
1
Plane mirror dimensions
475 mm x 40 mm x 45 mm
Number of gratings
4
Gratings dimensions
160 mm x 40 mm x 40 mm
Support structure
Adjustment ranges
Vertical translation
± 5 mm
Lateral translation
± 10 mm
Longitudinal translation
± 10 mm
Pitch
± 1°
Roll
± 1°
Yaw
± 1°
Plane mirror
Pitch rotation
Range
-0.89° to +9.35°
Resolution (design value)
0.0039 µrad /motor fine step
(1/64, recommended)
0.0097087 µrad /encoder count
Resolution (measured value)
0.05 µrad
Repeatability
0.20 µrad (pitch)
0.22 µrad (roll)
Long-term stability
(ca. 30 minutes)
0.017 µrad
Scanning speed
~ 680 µrad /s
Translation
Range
-0.054 mm to +35.83 mm
Resolution (design value)
0.013 µm /motor fine step
(1/64, recommended)
0.05 µm /encoder count
Long-term stability
(ca. 30 minutes)
0.022 µm
Gratings
Pitch rotation
Range
-0.98° to +8.24°
Resolution (design value)
0.0039 µrad /motor fine step
(1/64, recommended)
0.0097087 µrad /encoder count
Resolution (measured value)
0.05 µrad
Repeatability
0.23 µrad (pitch)
0.21 µrad (roll)
Long-term stability
(ca. 30 minutes)
0.017 µm
Scanning speed
~ 680 µrad /s
Translation (grating exchange)
Range
-0.04 mm to +200.1 mm
Resolution (design value)
0.013 µm /motor fine step
(1/64, recommended)
0.05 µm /encoder count
Long-term stability
(ca. 30 minutes)
0.022 µm
Performance Test Results
Pitch deviation after pitch change (mirror)
Roll deviation after pitch change (mirror)
Pitch deviation after pitch change (grating)
Roll deviation after pitch change (grating)
Mirror pitch positioning resolution
Mirror pitch long-term stability
Grating pitch positioning resolution
Grating pitch long-term stability
Mirror lateral position long-term stability
Grating lateral position long-term stability
Scanning speed of mirror pitch
Scanning speed of grating pitch
Residual gas analysis
