UE112_PGM-1

XUV undulator radiation variable polarization with PGM for meV RIXS

The UE112_PGM-1 is a low-energy high-flux beamline with the meV-RIXS permanent end station.

The optical layout of the beamline (all values are design parameters, dimensions given in mm). M1 is a toroidal mirror which collimates the light in the vertical plane and focusses in the horizontal plane on the horizontal apertures A4. The plane mirror M2 is used to vary the deviation angle at the plane grating G. Vertically, the diffracted light is focused onto the vertical apertures (exit slit A5) by the cylindrical mirror M3. The subsequent refocusing is performed by the KB type arrangement of the plane elliptical mirrors M4 and M5 in the horizontal and vertical directions, respectively.

The optical layout of the beamline (all values are design parameters, dimensions given in mm). M1 is a toroidal mirror which collimates the light in the vertical plane and focusses in the horizontal plane on the horizontal apertures A4. The plane mirror M2 is used to vary the deviation angle at the plane grating G. Vertically, the diffracted light is focused onto the vertical apertures (exit slit A5) by the cylindrical mirror M3. The subsequent refocusing is performed by the KB type arrangement of the plane elliptical mirrors M4 and M5 in the horizontal and vertical directions, respectively.


Station data
Temperature range Base temperature of liquid N2 and He, full temperature control in testing
Pressure range UHV range (<10-9 mbar)
More details meV RIXS
Beamline data
Segment H13
Location (Pillar) 15.1
Source UE112 (Elliptical Undulator)
Monochromator PGM with 3 gratings (300 l/mm, 600 l/mm and 1400 l/mm)
Energy range 8 - 690 eV; for extreme values (<50 eV or >400 eV) contact the beamline crew
Energy resolution 30,000 (20-150eV)
> 20,000 (150-350eV) (standard grating)
Flux > 2x1012 ph/s (20-280eV)
ca. 4x1013 ph/s (50-150eV) (standard grating)
Polarisation variable
Divergence horizontal mrad
Divergence vertical mrad
Focus size (hor. x vert.) optimum: ca. 0.001 x 0.02 mm (V x H, FWHM, inside sample chamber)
User endstation The fixed sample chamber allows the transmission of the beam. However, as there are no refocussing optics the beam is highly divergent and tilted at an 4 degree upward angle. 500 mm behind the last port, the beam dimensions are 1.7mm x 9.8 mm (V x H, FWHM).
Distance Focus/last valve -175 mm
Height Focus/floor level mm
Beam availability 12h/d
Phone +49 30 8062 14836
Polyimid foil (150 nm thick) Suppression at about 10 to 80 eV (foil installed)
Al foil (150 nm thick) Suppression at E > 73 eV (and < 15 eV) (foil installed)
Mg foil (240 nm thick) Suppression at E > 50 eV (and < 11 eV) (foil installed)
low-energy suppression Suppression of photon energies slightly above 21 eV, requires user installation of absorption foils. Materials such as Europium (Eu) or Neodymium (Nd) are suggested for this case.
TRIBS usage possible, with limitations, ask the beamline scientist
Absolute Flux Curve (2013/2014, log scale)

Absolute Flux Curve (2013/2014, log scale)


For further information about the insertion device (ID) see:

Bahrdt et al., “Compensation of Beam Line Polarizing Effects at UE112 of BESSY II,” 2010, pp. 335–338. DOI: 10.1063/1.3463205

For information about the Monochromator consult:

R. Follath and F. Senf, “New plane-grating monochromators for third generation synchrotron radiation light sources,” Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, vol. 390, no. 3, pp. 388–394, May 1997. DOI: 10.1016/S0168-9002(97)00401-4

Other beamline related literature:
R. Follath, F. Senf, and W. Gudat, “Plane-grating monochromator at BESSY II using collimated light,” Journal of Synchrotron Radiation, vol. 5, no. 3, pp. 769–771, May 1998. DOI: 10.1107/S090904959800079X