Structure and dynamics of the4p→ns,mdautoionizing resonances between the3Pand1Sthresholds in atomic bromine

Abstract

The relative partial photoionization cross sections ${\ensuremath{\sigma}}_{i}$ and photoelectron angular distribution parameters ${\ensuremath{\beta}}_{i}$ are measured for all possible final ionic states of ${\mathrm{Br}}^{+}$ between the ${}^{3}{P}_{2}$ and ${}^{1}{S}_{0}$ thresholds. The decay patterns of the autoionizing ${4p}^{4}{}^{3}{P}_{1,0}n\mathcal{l}$, ${4p}^{4}{}^{1}{D}_{2}n\mathcal{l}$, and ${4p}^{4}{}^{1}{S}_{0}n\mathcal{l}$ Rydberg series arising from the $4\stackrel{\ensuremath{\rightarrow}}{p}ns,md$ excitations are observed at the fine-structure level in all available channels. For each Rydberg series, the energies, quantum defects, and photoelectron angular distribution parameters are determined, as well as the widths and shape parameters of the low-lying members. Relative total cross sections are derived from the partial cross sections and from ion-yield measurements over the lowest members of the ${}^{3}{P}_{1,0}$ and ${}^{1}{D}_{2}$ series. All major spectroscopic and dynamic properties of these series are reported for this open-shell atom. Conclusions are drawn from the comprehensive data sets in comparison with other halogen atoms and the neighboring closed-shell rare gas atoms. Our results, encompassing the entire autoionization regime, are compared with other experimental data and theoretical calculations, where available.