Rotationally resolved electron-photon coincidence study of H2(d 3 Pi u) excitation

The three normalized Stokes' parameters characterizing the decay of the electron impact excited d 3 Pi u (V1=O, N1=1) rotational level of H2 were determined in an electron-photon coincidence experiment at 25 eV impact energy and 60 deg scattering angle. The low degree of polarization (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.