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Methoden und Instrumentierung Poster: Mi., 14:00–16:30 M-P84
Upgrading of the SKAT texture diffractometer at the IBR-2 pulsed neutron
source in Dubna, Russia
Klaus Ullemeyer 1 , Jan H. Behrmann 1
1 Geologisches Institut, Universität Freiburg, Albertstr. 23B, 79104 Freiburg
The TOF texture diffractometer SKAT [1] at the IBR-2 pulsed neutron source of the
Frank Laboratory of Neutron Physics in Dubna is operated by German scientists and
mainly used by Earth scientists due to advantages (in particular, high resolution) for
texture investigations on polyphase rock samples. The pulse repetition rate of 5 s −1
at IBR-2 reactor limits the maximum accessible range of lattice spacings d to about
4.9 ˚A. This may be sufficient for texture analyses on many polyphase rocks composed
of high-symmetrical constituents, however, successful texture analyses on rocks containing
low-symmetrical constituents may be hampered. Hence, we intend to expand
accessible d-range, which may be achieved by decreasing the scattering angle 2Θ. We
consider construction of a multidetector system with the detectors located at 2Θ =
65 ◦ . Accessible d-range extends to about 6.5 ˚A, giving access to more non-overlapped
Bragg reflections. Deterioration of resolution by about 15-20 % appears to be acceptable.
In addition, the single-axis sample goniometer will be expanded by two more
scanning axes, allowing more complex sample movements and the recording of orientational
data for alternative methods of quantitative texture analysis.
[1] Ullemeyer et al., Nucl. Instr. Meth. Phys. Res. A412 (1998), 80.