Transfer Excitation Processes Observed in N super( 3+)-He and O super( 3+)-He Collisions at E sub( lab) = 33 eV

We measured the relative state-selective differential cross sections (DCSs) for one-electron capture reactions using a crossed-beam apparatus. The scattering angle ... studied in the laboratory frame ranged from -3.0 to 22... and the laboratory collision energy E sub( lab) was 33 eV. Only the transfer excitation processes, i.e., the electron capture reactions with the simultaneous excitation of the projectile, were observed. The DCSs were determined for the following reactions: N super( 3+) (1s super( 2) 2s super( 2) super( 1)S) + He (1s super( 2) super( 1)S) ... N super( 2+) (1s super( 2) 2s2p super( 2) super( 2)D) + He+ (1s super( 2)S) + 10.3 eV, O super( 3+) (1s super( 2) 2s super( 2) 2p super( 2)P) + He (1s super( 2) super( 1)S) ... O super( 2+) (1s super( 2) 2s 2p super( 3) super( 3)P) + He+ (1s super( 2)S) + 12.7 eV, and O super( 3+) (1s super( 2) 2s super( 2) 2p super( 2)P) + He (1s2 1S) ... O super( 2+) (1s super( 2) 2s 2p super( 3) super( 3)D) + He+ (1s super( 2)S) + 15.5 eV. In the N super( 3+)-He system, the DCSs for the reaction are zero at the center-of-mass angle ... = 0 and show a peak at a certain angle and a shoulder at a larger angle. In the O super( 3+)-He system, the DCSs are again zero at ... = 0. The capture process to the O super( 2+) (1s super( 2) 2s 2p super( 3) super( 3)P) state is mainly observed at smaller scattering angles, and the reaction to the O super( 2+) (1s super( 2) 2s 2p super( 3) super( 3)D) state becomes dominant with increasing scattering angle. A classical trajectory analysis within the two-state approximation based on the ab initio potentials for (NHe) super( 3+) revealed that the transfer excitation of a two-electron process takes place through a single crossing of the relevant potentials. (ProQuest: ... denotes formulae/symbols omitted.)