Sökning: "relativistic atomic theory"

Visar resultat 1 - 5 av 22 avhandlingar innehållade orden relativistic atomic theory.

  1. 1. Theoretical Atomic Spectroscopy of Earthbound and Stellar Plasma

    Författare :Jon Grumer; Matematisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; atomstruktur; atomära processer; elektronkorrelation; plasmaspektroskopi; magnetfält; hyperfinstruktur; solkoronan; rymdväder; förekomst av grundämnen i stjärnor; datorsimuleringar; Zeemaneffekt; relativistiska effekter; atomic structure; atomic processes; computer simulation; electron correlation; relativistic atomic theory; plasma spectroscopy; Zeeman effect; magnetic fields; hyperfine structure; solar corona; space weather; stellar abundances; Fysicumarkivet A:2016:Grumer;

    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. 2. Spectroscopic Investigations of Highly Charged Tungsten Ions - Atomic Spectroscopy and Fusion Plasma Diagnostics

    Författare :Joel Clementson; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; extreme ultraviolet spectra; spheromak; electron beam ion trap; magnetic fusion; tungsten; highly charged ions; atomic structure; x-ray spectroscopy; plasma diagnostics; Fysicumarkivet A:2010:Clementson;

    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

  3. 3. Insights into Materials Properties from Ab Initio Theory : Diffusion, Adsorption, Catalysis & Structure

    Författare :Andreas Blomqvist; Rajeev Ahuja; Christopher Wolverton; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Density functional theory; Molecular dynamics; Diffusion; Catalysis; Adsorption; Random structure search; Hydrogen-storage materials; Phase-change materials; Defects and diffusion; Defekter och diffusion; Surfaces and interfaces; Ytor och mellanytor; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    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

  4. 4. Laser-Matter Interactions at Extreme Irradiance: X-ray Generation and Relativistic Channelling

    Författare :Anders Sjögren; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; relativistic self-focusing; particle acceleration; x-ray generation; radiography; Laserteknik; Laser technology; laser-produced plasma; light scattering; Fysicumarkivet A:2002:Sjögren;

    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

  5. 5. Theoretical Studies of Atomic Structure, Radiative Transitions and Interference Effects

    Författare :Martin Andersson; Fysiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Naturvetenskap; Natural science; Computational physics; Zeeman; Transition rate; Lifetime; Hyperfine structure; Interference; Atomic structure;

    Sammanfattning : Theoretical calculations concerning the advanced understanding of atomic structure and transitions has been performed for some atomic systems. The importance of different types of correlation depending on system has been investigated both using relativistic and non-relativistic quantum mechanics. LÄS MER