  We report on a versatile mini ultra-high vacuum (UHV) chamber which is
designed to be used on the MAgnetic Reflectometer with high Incident Angle of
the J\"ulich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum in
Garching, Germany. Samples are prepared in the adjacent thin film laboratory by
molecular beam epitaxy and moved into the compact chamber for transfer without
exposure to ambient air. The chamber is based on DN 40 CF flanges and equipped
with sapphire view ports, a small getter pump, and a wobble stick, which serves
also as sample holder. Here, we present polarized neutron reflectivity
measurements which have been performed on Co thin films at room temperature in
UHV and in ambient air in a magnetic field of 200 mT and in the Q-range of 0.18
\AA$^{-1}$. The results confirm that the Co film is not contaminated during the
polarized neutron reflectivity measurement. Herewith it is demonstrated that
the mini UHV transport chamber also works as a measurement chamber which opens
new possibilities for polarized neutron measurements under UHV conditions.
