State-Selective Differential Cross Section Measurements for the One-Electron Capture Process in C3+–He and C3+–Ne Systems at Elab = 33 eV

Abstract

Using a crossed-beam apparatus, we measured the relative state-selective differential cross sections (DCSs) for the following reactions: C3+ (1s2 2s 2S) + He (1s2 1S) → C2+ (1s2 2s2p 1P) + He+ (1s 2S) + 10.6 eV and C3+ (1s2 2s 2S) + Ne (2p6 1S) → C2+ (1s2 2p2 1D) + Ne+ (2p5 2P) + 8.2 eV. The scattering angle studied in the laboratory frame, θlab, was from −3.0 to 24°, and the laboratory collision energy Elab was 33 eV. In both systems, the DCSs for the reaction are zero at the center-of-mass angle θcm = 0, and show a peak at a certain angle and a broad hump at larger angles. A classical trajectory analysis within the two-state approximation based on the ab initio potentials for (CHe)3+ revealed that these structures observed are ascribed to the reactions that occur in different trajectories. The peak corresponds to the reactions occurring in the outgoing part of the trajectory, and the hump is associated with the reactions occurring mainly in the incoming part of the trajectory.