Stark broadening of singly ionized-silicon

Linewidths and shifts of the five prominent visible Si II multiplets are measured in a conventional shock tube. The Stark effect from impacting plasma electrons is the dominant broadening mechanism. Electron densities range widely [(4-15) × ${10}^{16}$ ${\mathrm{cm}}^{-3\mathrm{}}$], but temperatures (9500-12 500°K) do not. Optical depth and source inhomogeneity are rarely troublesome. Depending upon interference, blending, and signal-to-noise ratios, broadening-parameter accuracies are between 15-25% and shift uncertainties are 15-100%. Comparison data are examined.