Search for dissertations about: "Atomic Processes"

Showing result 1 - 5 of 270 swedish dissertations containing the words Atomic Processes.

  2. 1. Atomic Processes in Stellar Atmospheres : Inelastic Collisions and Effects on Late-type Spectra

    Author : Yeisson Fabian Martinez Osorio; Paul Barklem; Karin Lind; Nikolai Piskunov; Carlos Allende Prieto; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Spectral line: formation; atomic data; stellar abundances.; Fysik med inriktning mot astrofysik; Physics with specialization in Astrophysics;

    Abstract : Chemical abundances as measured from stellar spectral lines are often subject to uncertainties due to lack of accurate data for inelastic collisions, which is needed for non-local thermodynamic equilibrium (non-LTE) modelling. For cool stars, understanding of collision processes with electrons and hydrogen atoms is required to achieve high precision measurements. READ MORE

  4. 2. Theoretical Atomic Spectroscopy of Earthbound and Stellar Plasma

    Author : Jon Grumer; Matematisk fysik; []
    Keywords : 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;

    Abstract : 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. READ MORE

  5. 3. Dynamics and Atomic Processes in the Symbiotic Star AG Peg as Derived from Its Emission Line Spectrum

    Author : Mattias Eriksson; Astronomi - Genomgår omorganisation; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Astronomi; rymdvetenskap; kosmisk kemi; cosmic chemistry; space research; Astronomy; Atom- och molekylärfysik; Atomic and molecular physics; Symbiotic stars; Fluorescence; Atomic processes;

    Abstract : The spectra of symbiotic stars are shown to frequently contain numerous fluorescence lines caused by Photo-excitation by Accidental Resonance (PAR). So far, most work involving fluorescence in stellar spectra has been assigned to the search of new PAR mechanisms, which can explain the presence of certain emission lines. READ MORE

  6. 4. Electron - Ion Recombination Data for Plasma Applications : Results from Electron Beam Ion Trap and Ion Storage Ring

    Author : Safdar Ali; Reinhold Schuch; José R. Crespo López-Urrutia; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Highly charged ions; Atomic processes; Atomic data; Electron-ion recombination; Plasmas; fysik; Physics;

    Abstract : This thesis contains results of electron-ion recombination processes in atomic ions relevant for plasma applications. The measurements were performed at the Stockholm Refrigerated Electron Beam Ion Trap (R-EBIT) and at the CRYRING heavy-ion storage ring. READ MORE

  7. 5. Model-based Analysis and Design of Atomic Layer Deposition Processes

    Author : Anders Holmqvist; Avdelningen för kemiteknik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Atomic layer deposition; Heterogeneous reaction kinetics; Limit-cycle dynamics; Parameter estimation; Multi-objective optimization; Dynamic optimization; Scale-up analysis;

    Abstract : Atomic layer deposition (ALD) is a thin-film manufacturing process in which the growth surface is exposed to non-overlapping alternating injections of gas-phase chemical precursor species separated by intermediate purge periods to prevent gas-phase reactions. ALD is characterized by sequential self-terminating heterogeneous reactions between highly reactive gas-phase precursor species and surface-bound species which, when allowed sufficient conditions to reach saturation, results in highly conformal films, on both planar and topographically complex structures. READ MORE