Mathematisch-Naturwissenschaftliche Fakultät

Institut für Physik

Fachgebiet: Theoretische Physik

Betreuer: Prof. Dr. Heidi Reinholz

Dipl.-Phys. Andrea Sengebusch
(e-mail: )

Spectral line profiles of inner-shell x-ray transitions in dense plasmas

This thesis shows the applicability of characteristic x-ray lines of mid-Z materials to investigate the properties of warm and dense plasmas. Dealing with emitters with several occupied electron shells, the description of various excited and ionized states is of paramount importance.

To create warm, dense matter ultra-short high-intensity laser-pulses are used. Due to the solid density visible light cannot penetrate the target, but creates and accelerates free electrons that heat the sample. Moreover, the free electrons provide the basis for characteristic emission, which allows us to explore the target interior some picoseconds after the laser pulse.

A many particle quantum-statistical approach to emission line profiles is outlined. Further, a perturbative description of line profiles in dense plasmas based on a self-consistent ion sphere model is presented in detail. The controversial nature of the plasma polarization shift is scrutinized.

Assuming LTE-conditions the plasma composition is calculated to characterize the created warm, dense plasmas. Further, spectral line profiles are synthesized, which are used to analyze recent laser-plasma-experiments. Thus, we are able to explain changes of the line profiles of high resolution x-ray spectra with respect to the distance from the laser focus. Radial distrubutions of the plasma parameters are inferred and conclusions on the path of accelerated electrons are drawn.