Bruker Anton Paar, User Manual

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Adjustment of a Chamber on the D8
DOC-M88-EXX268_V1_12.2016 35
4 Adjustment of a Chamber on the
D8
The Anton Paar chamber has to be installed on the goniometer as described in chapter 5
and onward. This chapter discusses general alignment procedures. For chamber specific
details, we refer to the chapter discussing the chamber of interest.
4.1 Adjustment Procedures
It is assumed, that the diffractometer is aligned for the desired optics as described in [3]
(Vol.1 ch.
Alignment of the diffractometer ). The measurement parameters are given for
Cu-radiation.
1. Always check the 'ZI'-values of the diffractometer before aligning the chamber: Lower
the chamber to ensure, that the unaffected beam passes it.
2. Drive the θ-tube or θ-sample and 2θ-detector to the ZI-Values. Check the zero position
of the primary beam with a detector scan from -1° to 1° step size 0.006° (LYNXEYE
detector: 0D-mode with one opened strip, 0D-detector with receiving slit 0.1 mm, use
appropriate absorbers). If the maximum position is not 0° ± 0.01°, mount the standard
stage and repeat the glass slit adjustments.
Most chambers are supplied with a special tool. It creates a small slit used for proper
alignment of the chamber. Chambers without this tool can be aligned by performing a pro-
cedure that uses the shadow of the sample holder in the X-ray beam described as Alter-
native Method without Alignment Slit.
Two degrees of freedom need to be adjusted for the chamber: height and rotation. Height
influences low angle peak positions and rotation influences the resolution. The latter is
less critical, if you are mainly interested in lattice parameters and not in crystallite size
grain size determination.
When mounting the chamber the rotation of the chamber can be estimated and adjusted
by hand close to the optimum position, whereas the height is harder to adjust by eye. For
that reason it is recommended to align the height first.