  We report on the qualification of a piezo-based linear stage for the
manipulation of positions of dielectric discs in the booster of the MADMAX
axion dark matter search experiment. A first demonstrator of the piezo drives,
specifically developed for MADMAX, was tested at room temperature as well as at
cryogenic temperatures down to 4.5 K and inside strong magnetic fields up to
5.3 T. These qualification measurements prove that the piezo-based linear stage
is suited for MADMAX and fulfills the requirements.
