Elastic scattering, vibrational excitation, and attachment in low-energy electron- SF₆ scattering: Experiment and effective range theory

Cross sections at low energies for vibrationally elastic and inelastic scattering, as well as electron attachment to SF₆ , have been calculated using a multichannel effective range theory (ERT) with complex boundary conditions. The most active vibrational modes, the totally symmetric mode ν₁ and the infrared active mode ν₃ , have been included in the calculation. The ERT parameters were fitted to reproduce the experimental total and attachment cross sections. Differential elastic and vibrational excitation cross sections have been measured at 30° and 135° using a spectrometer with hemispherical analyzers. The calculation reproduces correctly the magnitudes and shapes of the differential elastic and ν₁ , ν₃ , and 2ν₁ excitation cross sections, in particular the sharp structures at vibrational thresholds. The s - and p -wave phase shifts obtained in the present analysis differ from those recently derived by Field et al. [Phys. Rev. A, 69, 052716 (2004)].