Molecular effects for alignment of excited hydrogen atoms produced by H i+ ( i = 1-3) ions passing through thin carbon foils
Stokes parameters of Balmer lines were measured for excited hydrogen atoms H 0 produced by beam-foil interactions of 0.5 MeV/amu H i+ ( i = 1-3) ions passing through thin carbon foils, 10 and 50 μg/cm 2. Alignment parameters along the collision axis, A0c, were determined under conditions of cylindrical geometry, that is, perpendicular incidence of ions on the foils. A0c are found to decrease with increasing i. This is in accord with the change of degree of spatial symmetry in outgoing dissociating fragments. The foil thickness dependence and the relative populations of magnetic quantum number m of H 0 are discussed.