Neutron Scattering

With triple axis instruments one can measure only step-by-step specific dynamic structure
factors S(Q, w) of interest . However, multi-detector instruments are more efficient for
measuring powders, for time-of-flight spectroscopy, or if langer regions in reciprocal space
need to be measured . The first instrument for such purposes is the D7, see Fig . 4 .14, at the
high flux reactor at the ILL in Grenoble ; 32 detectors are equipped for polarization analysis
. The polarizers are benders, curved stacks of polarizing supermirrors, which exhibit
good polarization and transmission properties for subthermal neutrons . In order to cover
Figure 4 .14 : The D7 at the ILL, a multi-detector instrument for polarization analysis .
On the right hand side one bank is shown in the non-polarizing version with analyzers
removed by pneumatic elevators and the collimators inserted instead of the guide fields .
With the spin turner coils the polarization of the neutrons can be rotated into the x,y, or
z direction . [14]
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