Huber-Diffraktometer at 20K with a Kapton-Zylinder

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Diffractometer	Kapton Cylinder	Crystal in Cylinder	Construction	Construction	Mounted Cylinder

The use of closed cycle Helium cryostat in low temperature diffraction experiments has considerable advantages in comparison to open flow systems, because the running cost are low and the temperature can be held stable for a long time. The normally in x-ray diffraction used Beryllium and Carbon chambers result in high background with powder lines. This is especially a problem on area detectors, because it is not possible to reduce the background with a detector collimator. To overcome this problem a vacuum chamber was construced from 0.1 mm Kapton film. This results in a very low background in comparison to a Beryllium cylinder. The use of this film without supporting material in the X-ray beem becomes possible through the construction of a two side support on a large Huber Diffractometer to span the film enough to hold atmospheric pressure. The construction has a low leak rate making it possible to measure some weeks at 25K. It is possible to use normal or metallized film so that the crystal is even visible with this setup. Crystals can be centered optical at low temperature.

Comparison of Kapton- and Be-Cylinder

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Berylium Cylinder

Kapton Cylinder

For further information contact
Marc Messerschmidt
AG Prof. Luger

The work was supported by DFG and DuPont(Kapton film)