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Visar resultat 1 - 5 av 25 avhandlingar som matchar ovanstående sökkriterier.
1. Theoretical Atomic Spectroscopy of Earthbound and Stellar Plasma
Sammanfattning : Motivated by spectroscopic analysis of astrophysical and laboratory plasma, this thesis concerns the fundamental structure and spectral properties of atoms and their ions. The multiconfiguration Dirac-Hartree-Fock (MCDHF) method is used to predict the emission or absorption of radiation, by atomic systems in general, and of heavy and highly charged ions in particular. LÄS MER
2. Atomic Electrons as Sensitive Probes of Nuclear Properties and Astrophysical Plasma Environments : A Computational Approach
Sammanfattning : This thesis deals with the relativistic modeling of atoms and ions. To interpret the stellar spectra and gain more insight from astrophysical observations, the underlying processes that generate the spectra need to be well understood and described. LÄS MER
3. Spectroscopic Investigations of Highly Charged Tungsten Ions - Atomic Spectroscopy and Fusion Plasma Diagnostics
Sammanfattning : The spectra of highly charged tungsten ions have been investigated using x-ray and extreme ultraviolet spectroscopy. These heavy ions are of interest in relativistic atomic structure theory, where high-precision wavelength measurements benchmark theoretical approaches, and in magnetic fusion research, where the ions may serve to diagnose high-temperature plasmas. LÄS MER
4. Insights into Materials Properties from Ab Initio Theory : Diffusion, Adsorption, Catalysis & Structure
Sammanfattning : In this thesis, density functional theory (DFT) calculations and DFT based ab initio molecular dynamics simulations have been employed in order to gain insights into materials properties like diffusion, adsorption, catalysis, and structure. In transition metals, absorbed hydrogen atoms self-trap due to localization of metal d-electrons. LÄS MER
5. Laser-Matter Interactions at Extreme Irradiance: X-ray Generation and Relativistic Channelling
Sammanfattning : This thesis summarizes experimental work in which the powerful Ti:sapphire lasers at the High Power Laser Facility at the Lund Laser Centre have been employed to investigate laser-produced X-rays and relativistic channelling. These lasers produce short pulses, of the order of 50 fs, with energies ranging from 1 mJ to 1 J. LÄS MER