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

The spectral dependence of the angular distributions of photoelectrons produced by the single-photon detachment of Sn^- [core, (5s², 5p³)] 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 Sn^- 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.