P389 – VLS-PGM SiP ME2 SSRF
Application
Plane grating monochromator (PGM) for soft X-ray synchrotron radiation
Year of delivery
2015
Installation site
SiP ME2 beamline at synchrotron radiation source SSRF, China
Design Features
-
High-resolution grazing incidence variable line spacing plane grating monochromator (VLS-PGM).
- Spectral range: 40 – 2000 eV.
- Optical elements: one plane mirror and three VLS plane gratings.
- Temperature sensors at the internal mechanics.
-
Active water cooling of all optical elements.
-
Motion control system with EPICS interface.
- Permanently installed bakeout provisions.
- Adjustable support structure.
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)
1300 mm
Beam offset
21 mm
Number of plane mirrors
1
Plane mirror dimensions
410 mm x 50 mm x 60 mm
Number of gratings
3
Gratings dimensions
180 mm x 40 mm x 50 mm
Support structure
Adjustment ranges
Vertical translation
± 15 mm
Lateral translation
± 15 mm
Longitudinal translation
± 15 mm
Pitch
± 1.5 °
Roll
± 1.5°
Yaw
± 1.5°
Plane mirror
Pitch rotation
Range
+1° to -12.5°
Resolution (design value)
0.00375 µrad /motor fine step
(1/64, recommended)
0.0097087 µrad /encoder count
Resolution (measured value)
0.05 µrad
Repeatability
0.20 µrad (pitch)
0.35 µrad (roll)
Long-term stability (> 45 minutes)
0.03 µrad
Scanning speed
~720 µrad /s
Gratings
Pitch rotation
Range
-1° to -12.5°
Resolution (design value)
0.00375 µrad /motor fine step
(1/64, recommended)
0.0097087 µrad /encoder count
Resolution (measured value)
0.05 µrad
Repeatability
0.24 µrad (pitch)
0.29 µrad (roll)
Long-term stability (> 45 minutes)
0.02 µrad
Scanning speed
~700 µrad /s
Translation
Range
-43.8 mm to +154.2 mm
Resolution (design value)
0.04 µm /motor fine step
(1/128, recommended)
0.05 µm /encoder count
Repeatability
0.24 µrad (pitch)
2.40 µrad (roll)
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)
Pitch deviation after grating translation
Roll deviation after grating translation
Mirror pitch positioning resolution
Mirror pitch positioning resolution
Grating pitch positioning resolution
Grating pitch positioning resolution
Mirror pitch long-term stability
Grating pitch long-term stability
Scanning speed of mirror pitch
Scanning speed of grating pitch
Residual gas anaysis
