The Trojan-horse method has been suggested as a means to study a two-body r
eaction at astrophysical energies via a three-body breakup reaction. In ord
er to test this method the Li-6(C-12,alpha(12)C)H-2 reaction was studied in
a kinematically complete experiment at an incident energy of 18 MeV. Coinc
idence spectra show the presence of the quasi-free alpha-C-12 scattering pr
ocess. The excitation function of the three-body reaction is calculated in
the plane wave impulse approximation assuming quasi-free scattering and is
compared with the experimental data. Also, the excitation function of the v
irtual a-12C elastic scattering is extracted from the three-body reaction c
ross section at low deuteron momenta and compared with the behaviour of the
free scattering cross section.