Photodetachment of SF6−

The photodetachment cross section for SF6− and the photodetachment threshold for this process have been accurately measured using a newly developed technique. The photodetachment cross section has a threshold at 3.16 eV which is about three times larger than the electron affinity of the SF6 molecule. The magnitude of the photodetachment cross section increases monotonically from the threshold to 1.0 × 10−8 cm2 at a photon energy of 3.46 eV. The small size of the measured cross section is attributed to the large relaxation in the equilibrium internuclear positions of SF6− compared to SF6; the analysis of the data indicates that the photoejected electron has an angular momentum quantum number l = 1.