Selected transition probabilities in singly ionized bismuth atoms

Abstract

This paper contains experimentally determined values for the spontaneous emission transition probabilities (Einstein's coefficient $A$) of 9 seleced transitions in singly ionized bismuth atoms (Bi II). Laser-Induced Plasma (LIP) was used as a source of the optical emission spectra. Due to LIP spatial inhomogeneity, the inverse Abel transform method was applied to lateral LIP profiles recorded in side-on geometry. The relative intensities of spectral lines were measured as the area under a spectral line profile curve fitted to the Voigt function. The Saha-Boltzmann plot of three consecutive ionization states from Bi spectra was constructed assuming Local Thermodynamic Equilibrium (LTE) in LIP and served for electron temperature estimation. The electron density was estimated based on the Stark width measurement of a well-investigated diagnostic He I 388.86 nm spectral line. The Saha-Boltzmann fit parameters were used for deducing the $A$ values. The uncertainties for every value of $A$ were obtained through the error propagation procedure of errors in measured quantities as well as the Monte Carlo method.