Electron-impact widths and shifts of Sr II lines in ultracold neutral plasmas

摘要

In this paper, we report on relativistic quantum-mechanical calculations of electron-impact linewidths and linenshifts in singly ionized strontium ions in ultracold neutral plasmas.We have used the Dirac R-matrix methods tonsolve (N + 1)-electron colliding systems and to generate the required scattering matrices. Calculated linewidthsnand line shifts at an electron density 1017 cm−3 and electron temperatures (several electronvolts) agree wellnwith other theoretical calculations and are closer to the experimental observations. Our theoretical findings ofnlinewidths and line shifts are almost twice as large as the earlier calculations for the particular selected plasmanconditions. This work develops these quantum-mechanical procedures and applies them to the emission fromnultracold neutral plasmas.