Sökning: "oscillator strengths"

Visar resultat 11 - 15 av 19 avhandlingar innehållade orden oscillator strengths.

  1. 11. Measurements of oscillator strenghts in Zr II and Cr II

    Författare :Gunilla Ljung; Astronomi - Genomgår omorganisation; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Experimental oscillator strenghts (f-values) for lines in Zr II and Cr II have been determined using branching fractions (BFs) and radiative lifetimes. Experimental log gf-values for 263 spectral lines in Zr II have been derived by combining previously measured lifetimes with new BFs measured on the Lund UV Fourier Transform Spectrometer (FTS). LÄS MER

  2. 12. Experimental and Computational Atomic Spectroscopy for Astrophysics : Oscillator strengths and lifetimes for Mg I, Si I, Si II, Sc I, and Sc II

    Författare :Asli Pehlivan Rhodin; Astronomi - Genomgår omorganisation; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Atomic Data; Astrophysics - Solar and Stellar Astrophysics;

    Sammanfattning : Atomic data such as oscillator strengths and wavelengths are important for astrophysical applications as they have a crucial role in determining abundances of specific elements in a star, a galaxy, or any object emitting radiation in the space. Stars in the Galaxy mostly keep the composition of the interstellar gas from which they were formed, therefore studying stellar abundances helps us understand how the Milky Way was formed and how it evolved. LÄS MER

  3. 13. Spectral Analysis of Neutron Capture Elements in the Laboratory and Stars

    Författare :Martin Lundqvist; Astronomi - Genomgår omorganisation; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; cosmic chemistry; Astronomy; space research; Atom- och molekylärfysik; Atomic and molecular physics; Astronomi; Sm; Hf; Os; Ir; Neutron capture processes; rymdvetenskap; kosmisk kemi; cool stars; Spectroscopy; atomic data;

    Sammanfattning : The pedigree of the elements heavier than iron is a vital question in the history and evolution of our galaxy. The elements up to and including those of the iron group are produced mainly through fusion processes within stars, giving the stars their energy. LÄS MER

  4. 14. Atomic Influences in Stellar Spectroscopy

    Författare :Krister Nielsen; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; magnetic and optical properties; supraconductors; magnetic resonance; relaxation; Kondenserade materiens egenskaper:elektronstruktur; spectroscopy; rymdvetenskap; kosmisk kemi; Astronomi; Astronomy; spektroskopi; magnetisk resonans; supraledare; magnetiska och optiska ; egenskaper elektriska; space research; cosmic chemistry; stellar magnetic fields; branching fractions; spectral line structure; Fysicumarkivet A:2002:Nielsen; Condensed matter:electronic structure; line blending; electrical;

    Sammanfattning : This thesis is a description of how knowledge of atomic physics can be used in a stellar spectrum analysis. Stellar investigations are spectroscopically performed based on wavelengths, intensities and spectral line structure. LÄS MER

  5. 15. Stark Spectroscopy, Lifetimes and Coherence Effects in Diatomic Molecular Systems

    Författare :Annie Hansson; Peder Royen; Michel Herman; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; diatomic; dipole moment; Stark effect; lifetimes; transition moment; coherence effects; EIT; Autler-Townes; Chemical physics; Kemisk fysik;

    Sammanfattning : In this dissertation is exemplified how different laser based methods are applied in high-resolution spectroscopic studies of internal properties of diatomic molecules.A molecular beam apparatus assembly is described, where a laser ablation source is combined with a time-of-flight mass spectrometer. LÄS MER