Experience with the 1D silicon strip LynxEye detector

J. Maixner

Central Laboratories, Institute of Chemical Technology Prague, Technická 5, 166 28 Prague 6, Czech Republic
maixnerj@vscht.cz

The LynxEye is a 1-dimensional detector for X-ray powder diffraction based on Bruker silicon strip technology capable to detect the X-ray energy from 6 keV to 15keV. The active area of the detector is 14.4x16mm and consists of 192 strips which act as individual detectors. Each strip is 75mm wide and its maximum local count rate is about 650.000 cps, so the maximum global count rate of the detector is about 100.000.000cps. The maximum 2-theta range simultaneously covered is 3.773° in the case of 435 mm measurement circle diameter. It is the maintenance–free detector with no need for counting gas, cooling water or liquid nitrogen. It can be used not only as 1-D detector but as well as 0-D detector with XRD Commander version 2.6 or higher. The 0-D version seems to be useful for the adjustment of the diffractometer and for performing some type of scans like rocking curve or tube scan which are not available in 1-D mode.

The LynxEye detector can dramatically increase of about 200 times the counting statistics respect to a point detector which can bring the following benefits.

· The number of measured powder patterns(standard amount of sample 100-200 mg) may be about 5-10/hour with much better counting statistics respect to a point detector – a higher throughput rate of the diffraction system, improving detection limits of crystalline phases up to 0.1%. Even weak reflections can be identified making qualitative phase analysis faster and more reliable

• Possibility to measure low amount of sample (1mg-100mg) in a reasonable time from 1- 10 hours producing powder patterns suitable for qualitative phase analysis – X-ray microdiffraction

• Possibility to measure sample fixed into capillary (about 20mg) producing almost texture-free powder patterns or to measure unstable compounds

• Possibility to perform temperature dependent measurements to study phase transformation in situ. If the 2-theta range can be limited to 3.773°, the PSD fix scan may be used and statistically reasonable powder pattern collected in 6s, so the sample can be continuously heated with the speed of 10°C/min and results compared with DTA or TGA measurements

References

1. LynxEye Detector User Manual, Bruker AXS GmbH, Karlsruhe, Germany, May 14, 2008.

Acknowledgements.

This work was supported by project 203/07/0040 of the Grant Agency of the Czech Republic and project MSM 2B08021 of the Ministry of Education,Youth and Sports of the Czech Republic.