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First test of a large-surface X-ray detector for low photon energies

13.09.2012

Figure 1: Small Angle X-ray scatter diagram of a multi-lamellar liposome sample, recorded at a photon energy of 3 keV with a vacuum-compatible Pilatus detector at the FCM beamline of PTB at BESSY II

In cooperation with PTB, the Swiss company Dectris has developed a vacuum-compatible version of the "Pilatus" hybrid pixel detector for X-rays. This device now allows, for example, experiments for the size determination of nanoparticles to be carried out with Small Angle X-ray Scattering (SAXS) also around the absorption edges of light elements like calcium, sulfur, phosphor or silicon at photon energies below 5 keV with high dynamics and good spatial resolution. This is of particular importance for the investigation of biological samples, for example within the scope of projects of the European Metrology Research Programme (EMRP), in the case of which complicated biological nano-objects and nanoparticles in complex biological matrices are to be dimensionally characterized in the PTB laboratory at the electron storage ring BESSY II, using SAXS measurements with synchrotron radiation. The device was delivered in June 2012 and has meanwhile been successfully put into operation. In cooperation with the Helmholtz Centre Berlin and the Institute for Molecular Pharmacology of the Hungarian Academy of Sciences, first SAXS images of a multi-lamellar liposome sample were recorded on the Four Crystal Monochromator (FCM) beamline in the PTB laboratory at BESSY II at a photon energy of 3 keV and presented – already in July 2012 – at the international conference on Synchrotron Radiation Instrumentation (Figure 1). The new detector consists of 10 modules which furnish – with a pixel size of 172 µm – a total area of 17 cm x 18 cm. It shall also be used for wide-angle scattering (WAXS), small-angle scattering in reflection under grazing incidence (GISAXS) and for other X-ray techniques.

Contact person:         

M. Krumrey, 7.11, e-mail: Michael.Krumrey@ptb.de