Layout/Characteristics


The beamline can either be operated in monochromatic, pink or white beam mode. The key parameters of the beamline are summarized in the table at the end of this section. The main optical elements are a Rh coated Si mirror and the double crystal monochromator (DCM). The mirror allows to cut the energy spectrum of the incident photons at its higher end to suppress the harmonic content in the monochromatic beam. In addition, it is used to focus the beam in the vertical direction. The DCM consists of a flat Si(111) single crystal and a sagittal Si(111) crystal bender for horizontal focusing. The position of the incident X-ray beam is traced by a blade beam position monitor in front of the optics. The outgoing beam can be monitored by the insertion of a fluorescence screen at the end of the optics. In case of the point detector, two pairs of horizontal and vertical slits allow to pre-select the beam size on the sample.

 

Schematic view of the MPI beamline at KARA – the sample is present in the horizontal geometry (sample normal vertical). Taken from: M. Delheusy, J. Major, A. Rühm, A. Stierle. Dedicated beamlines for in-situ investigations of materials in reduced dimensions. International Journal of Materials Research 102, 913 (2011).

 

Source

1.5 T Bending magnet (Ec = 6 keV), 0.3 mrad horizontal, 0.03 mrad vertical

Energy range

6 keV - 20 keV
With focusing: 6 keV – 10 keV

 

Optics

Double crystal monochromator with a pair of Si(111) crystals, second crystal allows horizontal focusing of the beam
Rh coated mirror, vertical focusing possible

Energy resolution (ΔE/E)

3·10-4 @ 9 keV

Flux at sample position

1.0·10+12 ph/s/0.1% bw @ 9 keV

Sample environment

HT oven, cryostat, Kapton dome with He atmosphere, fast capillary spinner

Beam size at sample

could be focused to 0.3 mm (Hor) x 0.2 mm (Ver)

Experimental setup / sample positioning

Multiple circle diffractometer, horizontal / vertical sample normal geometry, horizontal / vertical four circle geometry, COR 5m from DCM

Experimental setup / detectors

Mythen 1K 1D-detector (50 μm x 8 mm, 700 Hz),
Pilatus 100k 2D-detector (172 x 172 μm2),
Eiger 500K 2D-detector (75 x 75 μm2, 9 kHz)
MAR165 CCD 2D-detector,
NaI(Tl) scintillation counter,
LaCl3 scintillation counter,
10 x 10 mm² Avalanche photodiode,
Si/Ge energy dispersive detector

Software: Control system / Data treatment / evaluation

SPEC, software for reciprocal space mapping, software for reflectivity and crystal truncation rod analysis

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