title: Plasma pressure broadening for few-electron emitters including strong electron collisions within a quantum-statistical theory.
abstract: To apply spectroscopy as a diagnostic tool for dense plasmas, a theoretical approach to pressure broadening is indispensable. Here, a quantum-statistical theory is used to calculate spectral line shapes of few-electron atoms. Ionic perturbers are treated quasistatically as well as dynamically via a frequency fluctuation model. Electronic perturbers are treated in the impact approximation. Strong electron-emitter collisions are consistently taken into account with an effective two-particle T-matrix approach. Convergent close-coupling calculations give scattering amplitudes including Debye screening for neutral emitters. For charged emitters, the effect of plasma screening is estimated. The electron densities considered reach up to n(e) = 10(27) m(-3). Temperatures are between T = 10(4) and 10(5) K. The results are compared with a dynamically screened Born approximation for Lyman lines of H and H-like Li as well as for the He 3889 Å line. For the last, a comprehensive comparison to simulations and experiments is given. For the H Lyman-α line, the width and shift are drastically reduced by the Debye screening. In the T-matrix approach, the line shape is notably changed due to the dependence on the magnetic quantum number of the emitter, whereas the difference between spin-scattering channels is negligible.
authors.affiliation: Institute of Physics, University of Rostock, D-18051 Rostock, Germany.
authors.forename: Sonja
authors.initials: S
authors.lastname: Lorenzen
authors.affiliation: Institute of Physics, University of Rostock, D-18051 Rostock, Germany.
authors.forename: Banaz
authors.initials: B
authors.lastname: Omar
authors.affiliation: Institute of Theoretical Physics, Curtin University, Perth, Western Australia 6845, Australia.
authors.forename: Mark C
authors.initials: MC
authors.lastname: Zammit
authors.affiliation: Institute of Theoretical Physics, Curtin University, Perth, Western Australia 6845, Australia.
authors.forename: Dmitry V
authors.initials: DV
authors.lastname: Fursa
authors.affiliation: Institute of Theoretical Physics, Curtin University, Perth, Western Australia 6845, Australia.
authors.forename: Igor
authors.initials: I
authors.lastname: Bray
mesh_terms: D003198:Computer Simulation; D004583:Electrons; D008956:Models, Chemical; D015233:Models, Statistical; D017711:Nonlinear Dynamics; D058626:Plasma Gases / Q000737:chemistry*; D011789:Quantum Theory
chemical_list: D058626:Plasma Gases