Plasma-Broadened Cesium Lines

Abstract

Profiles of isolated plasma-broadened lines have been calculated and measured for the fundamental series ($5D\ensuremath{-}nF$) of cesium. The calculations used the static theory for the ion interactions and the classical path, nonadiabatic impact approximation for the electron interactions. The necessary matrix elements have been obtained from wave functions specially determined for this purpose. The calculations were made for plasma ion densities in the range from 3\ifmmode\times\else\texttimes\fi{}${10}^{13}$ to 1\ifmmode\times\else\texttimes\fi{}${10}^{16}$ ${\mathrm{cm}}^{\ensuremath{-}3}$ and temperatures from 2000\ifmmode^\circ\else\textdegree\fi{} to 10 000\ifmmode^\circ\else\textdegree\fi{}K. A scanning monochromator was used to measure profiles of lines emitted from a hot-cathode low-voltage discharge. Plasma densities and electron temperatures were determined from continuum intensity measurements. Line intensities were also measured. Observations were made at ion densities from 3.2\ifmmode\times\else\texttimes\fi{}${10}^{13}$ to 1.6\ifmmode\times\else\texttimes\fi{}${10}^{15}$ ${\mathrm{cm}}^{\ensuremath{-}3}$ with temperatures between 2300\ifmmode^\circ\else\textdegree\fi{} and 6000\ifmmode^\circ\else\textdegree\fi{}K. Experimental and theoretical widths are presented and compared. The ratio of measured to calculated width averaged over the data points is 0.99\ifmmode\pm\else\textpm\fi{}0.18. The widths are nearly proportional to ion density and are insensitive to temperature. Predicted values of line shift are also given.