  A comparison of the close-to-threshold total cross sections for the eta-prime
meson production in both the pp --> pp eta-prime and pn --> pn eta-prime
reactions should provide insight into the flavour-singlet (perhaps also into
gluonium) content of the eta-prime meson and the relevance of quark-gluon or
hadronic degrees of freedom in the creation process. The excitation function
for the reaction pp --> pp eta-prime has been already established. At present,
experimental investigations of the quasi-free pn --> pn X reactions are carried
out at the COSY-11 facility using a beam of stochastically cooled protons and
the deuteron cluster target. A method of measurement and preliminary results
from the test experiments of the pn --> pn eta reaction are presented in this
report.
