HK4 - Multipurpose Double Axis Diffractometer SPN-100
The two-axis diffractometer SPN-100 is equipped with bent Si and Ge perfect single crystal monochromators easily changeable according to the experimental requirements. The diffractometer is usually used for macro/micro strain scanning of polycrystalline materials. An easy change of the instrument parameters permits one to use it also for another type of experiments. The diffractometer uses advantages coming from focusing both in real and momentum space and yields good resolution and luminosity especially for samples of small dimensions. The resolution properties of the device arereached in a limited Q-range for which the focusing conditions are optimized. The corresponding optimization can be done easily by using a remote control of the curvature of the monochromator. Depending on the sample-detector distance and the required resolution the PSD detector can cover 7° (15°) of the scattering angle 2QS. In the case of the strain scanning of the sample, the gauge volume is determined by two fixed Cd slits (2-5)x(3-30) mm2 in the incident and diffracted beams and the measurements are performed in the vicinity of 2QS=90°. For scanning the sample a x-y-z stage can be used. The instrument is controlled by PC. Recently, the diffractometer has been equipped with a sandwich type monochromator consisting of two bent crystal slabs of different cuts providing two different neutron wavelengths simultaneously (Si(111) + Si(220), Si(220) + Ge(311)). This monochromator is mainly used for strain measurements when providing more sample reflections in the range of the investigated scattering angles.