Neutron Scattering

The instrument DNS [15] (see Fig . 4 .16) at the research reactor in Jülich is similar to
the D7 . The DNS has a comparably compact design . Different detector banks are used
for standard time-of-flight (TOF) mode and polarization analysis (typically combined
with TOF) . They are placed to the right and left, respectively, to the incoming beam .
The polarizers and analyzers are made of a stack of sputtered magnetic supermirrors,
alternating layers of FeCoV/Ti:N with a Gd :Ti absorbing antireflexion layer underneath
[l6] . The monochromatic beam is vertically and horizontally focused . Different to the
present version of the D7 (there are plans for an upgrade) the polarizers have a geometrical
design te use beam focusing on the sample with a substantial gain in intensity . A 1-lezeitype
(7r)-spin-flipper is used in combination with a Brookhaven correction coil, both made
of uncoated aluminum wires (for better transmission as compared to coated Cu-wires, for
instance) . The degree of polarization determined frein the intensities of non-spin-flip
Figure 4 .16 : The DNS instrument at Jülich equipped for 3-dim polarization analysis . The
detector bank to the right of the incoming beam is for unpolarized experiments the one
to the left for polarization analysis . A focusing layout lias been used for the initial and
final polarizers .
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