Plasma pressure broadening for few-electron emitters including strong electron collisions within a quantum-statistical theory
MetadataShow full item record
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 ne=1027 m-3. Temperatures are between T=104 and 105 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-a 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.
Showing items related by title, author, creator and subject.
Lorenzen, S.; Wierling, A.; Reinholz, H.; Röpke, G.; Zammit, Mark; Fursa, Dmitry; Bray, Igor (2012)We present results for the Lyman-a line of hydrogen in dense plasmas. Full line profiles are calculated within a quantum-statistical method, based on thermodynamic Green's functions. The contributions of plasma ions and ...
Lorenzen, S.; Wierling, A.; Reinholz, H.; Röpke, G.; Zammit, Mark; Fursa, Dmitry; Bray, Igor (2010)The electronic self-energy Se is an important input in a quantum-statistical theory for spectral line profile calculations. It describes the influence of plasma electrons on bound state properties. In dense plasmas, the ...
Omar, B.; González, M.; Gigosos, M.; Ramazanov, T.; Jelbuldina, M.; Dzhumagulova, K.; Zammit, Mark; Fursa, Dmitry; Bray, Igor (2014)Spectral line shapes of neutral helium 3889 Å(23S–33P) transition line are calculated by using several theoretical methods. The electronic contribution to the line broadening is calculated from quantum statistical ...