Summary 
The SKAT is a multi-detector diffractometer consisting of three independent detector systems. Each detector system is characterized by unique scattering geometry of the detectors. Selecting the optimum scattering angle 2θ allows adaptation of the accessible d-range and resolution Δd/d to sample requirements. If desired, the wavelength range may be expanded by an additional beam chopper, which covers every second neutron pulse. 
Instrument description 
The SKAT diffractometer comprises three ring-shaped carriers, each bearing up to 19 detector-collimator units located at 2θ = 65° / 90° and 135°, respectively. The three detector systems are developed for an alternative use, detector-collimator units are exchangeable between systems. Selection of a unique scattering angle for the detectors results in identical positions of the diffraction peaks, hence, all λ- and θ- dependent corrections can be avoided.
The 2θ = 65° detector system allows texture experiments with good resolution up to a maximum lattice spacing of d_max = 6.5 Å. A single sample resolution around an axis Z at an angle of 57.5° with respect to the incident neutron beam is sufficient to cover the whole pole figure. 
The 2θ = 90° detector system allows high resolution texture experiments up to a maximum lattice spacing of d_max = 5.0 Å. A single sample resolution around an axis Z at an angle of 45.0° with respect to the incident neutron beam is sufficient to cover the whole pole figure. The goniometer angle of 45° offers the optimum conditions for the installation of uniaxial sample environments for in situ experiments. 
The 2θ = 135° detector system allows very high resolution texture experiments up to a maximum lattice spacing of d_max = 3.9 Å. Two goniometer positions (Z at 22.5° and 67.5°) are required to cover the whole pole figure. 

Layout of the SKAT detector systems for alternative use. 
The sample is rotated around the axis Z, for the detector system 2θ = 135° two sample positions P₁ and P₂ 
are required. Sample movements around the X and Y axes are also possible.

Photograph of the SKAT with the detector system at 2θ = 90° and the goniometer for sample rotation (status December 2006)

Predicted resolution of the SKAT detector systems, derived from experimental data of the former neutron guide for sample rotation (status December 2006)

2θ-related parameters

2θ = 65°

2θ = 90°

2θ  = 135°

d_max

6.5 Å / 13.6 Å*

5.0 Å / 10.3 Å*

3.8 Å / 7.9 Å*

Best resolution Δd/d

6.2·10^-3

5.0·10^-3

3.1·10^-3

Secondary beam path

1.10 m

1.00 m

0.95 m

Cross section: 50 mm (w) × 90 mm (h)
Radius: 13400 m
Coating: natural Ni (m = 1)
Option: chopper covering every 2^nd neutron pulse

Set of 19 ³He single tube detectors
P = 4.5 bar
Ø = 60 mm

Two sets of Gd-coated soller collimators
Angular dispersion: 18' / 45'
Cross section: 55 × 55 mm²

SONIX software PC running MS Windows