Bruker VANTEC-1, User Manual

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System Description VÅNTEC-1 Detector User Manual
3 - 16 M88-E01072
3.4.3 Radial Soller Slit
The purpose of the radial Soller slit is to reduce
both primary and secondary air scatter which
influences the background of the diffraction pat-
tern. The peak intensity phases, with small sam-
ple amounts, are determined more easily and
can be detected earlier. The radial Soller slit is
needed for the linear detector VÅNTEC-1,
Göbel mirrors (Parallel beam geometry) or pri-
mary focusing monochromators in transmission
mode. The final settings have to be tested with
an intensity standard like NIST SRM1976
Corundum plate or NIST SRM640c Silicon pow-
der filled in capillaries.
NOTE: The radial Soller slit cannot be used with
Bragg-Brentano focusing geometry due to differ-
ence in the beam path. When using Göbel mir-
rors or primary monochromators, no K
β
filter is
needed. Fixed mode measurements will also fail
because only the center of the detector will
show useful signals.
The radial Soller slit has two degrees of freedom
(DOFs). Position the DOFs using dovetails and
fine adjustment screws (see Figure 3.14). The
first DOF is the translation movement along the
tangent of the measuring circle (tangent axis)
and the second is the radial movement along
the radius (radial axis).
Figure 3.14 - Radial Soller slit
Tangent
alignment
Radial
alignment