Abstract
The three normalised Stokes' parameters characterising the decay of the electron impact excited d3 pi u ( nu 1=0, N1=1) rotational level of H2 were determined in an electron-photon coincidence experiment at 25 eV impact energy and 60 degrees scattering angle. The low degree of polarisation (coherence) which was observed could be caused by both the averaging over the magnetic sublevels of the ground state of the target and the fine and hyperfine relaxation process. The average angular momentum transfer perpendicular to the scattering plane from the electrons to the molecules was found to be near zero in this excitation process.