Fine-structure-resolved measurements of photoelectron angular distributions by single-photon detachment ofSn−at visible wavelengths

Abstract

The spectral dependence of the angular distributions of photoelectrons produced by the single-photon detachment of ${\mathrm{Sn}}^{\ensuremath{-}} [\mathrm{core}, {(5s}^{2}, {5p}^{3})]$ ions has been measured at four discrete photon wavelengths ranging from 457.9 to 514.5 nm (2.71--2.41 eV) using a crossed laser-ion beams apparatus. Values of the fine-structure-resolved asymmetry parameters have been determined by fits to the photoelectron yield as a function of the angle between the photon polarization vector and the linear momentum vector of the collected photoelectrons. The measured asymmetry parameters for ${\mathrm{Sn}}^{\ensuremath{-}}$ are compared to previous asymmetry parameter measurements for negative ions with similar electronic configurations. The measurements were also fit to a previously reported model for photoelectron asymmetry parameters for photodetaching p-orbital electrons from negative ions.