  The study of DD reactions, especially with polarized reactants, helps for
better understanding of the processes taking place in nuclear astrophysics and
fusion reactors. At PNPI Gatchina, Russia, the PolFusion experiment with
crossing of two polarized beams, i.e. a deuteron and a deuterium beam, is able
to measure angular distributions of the differential cross section and,
therefore, the spin-correlations coefficients with different combinations of
the adjustable nuclear polarization of both beams with a center-of-mass energy
between 10 to 100 keV. Some improvements and fine-tuning of the polarized ion
source are performed and presented. The atomic beam source for the jet target
has been modified as well. An unpolarized experiment with a 10 keV ion beam and
heavy water vapor as a target has been carried out with successful registration
of the fusion products
