  In order to extend the available experimental database for the astrophysical
gamma-process, the cross section measurement of the 130Ba(alpha,gamma)134Ce and
130Ba(alpha,n)133Ce reactions is in progress. The measurements are carried out
using thin layers of evaporated BaCO3 as target. Since the target thickness
enters directly into the calculation of the cross sections, the reliability of
its determination is of crucial importance. Three different methods have been
used to determine the target thickness. Details of these experiments and the
obtained results are presented.
