Sökning: "Relativistic effects"

Visar resultat 1 - 5 av 66 avhandlingar innehållade orden Relativistic effects.

1. 1. Relativistic light-matter interaction

   Författare :Tor Kjellsson Lindblom; Eva Lindroth; Bernard Piraux; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Time-dependent Dirac equation; Beyond dipole effects; Relativistic effects; High-Intensity laser-matter interaction; teoretisk fysik; Theoretical Physics;

   Sammanfattning : During the past decades, the development of laser technology has produced pulses with increasingly higher peak intensities. These can now be made such that their strength rivals, and even exceeds, the atomic potential at the typical distance of an electron from the nucleus. LÄS MER

3. 2. Extending relativistic linear response theory to address solvent effects

   Författare :Joel Creutzberg; Beräkningskemi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Response theory; Polarizable embedding; Complex Polarization Propagator; Relativistic effects;

   Sammanfattning : The central aim of this thesis is to derive, implement and test new methods to calculate various types of spectroscopies of compounds containing heavy elements in an aqueous environment. Methods that can target such systems have to consider the following:(i) It is crucial to take relativistic effects into account. LÄS MER

4. 3. Relativistic light-matter interaction

   Författare :Tor Kjellsson; Eva Lindroth; Victor Kimberg; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; fysik; Physics;

   Sammanfattning : In this licentiate thesis light-matter interaction between hydrogen and superintense attosecond pulses is studied. The specific aim here is to identify for what intensities the non-relativistic calculations, given by solving the time dependent Schrödinger equation, no longer are valid. LÄS MER

5. 4. Extreme Electron Beams and Brilliant X-rays : Generation, Manipulation and Characterization of Relativistic Electron Beams for and from Plasma-Based Accelerators

   Författare :Jonas Björklund Svensson; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; laser; plasma; wakefield; acceleration; accelerator; relativistic; electrons; x-rays; ultra-fast; betatron; laser-wakefield acceleration; plasma-wakefield acceleration; Fysicumarkivet A:2020:Björklund;

   Sammanfattning : This thesis is based on work done by the author on the development of plasma-based electron accelerators driven by ultra-intense laser pulses and dense electron bunches. Plasma based accelerators have several benefits, such as accelerating fields around 1000 times stronger than in “conventional” radio-frequency accelerators, which can allow for shrinking the overall footprint of the accelerator. LÄS MER

7. 5. Atomistic spin dynamics and relativistic effects in chiral nanomagnets

   Författare :Konstantinos Koumpouras; Anders Bergman; Olle Eriksson; Manuel Pereiro; Elena Vedmenenko; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : In this thesis, studies based on magnetization dynamics on atomic length scales are presented for a number of magnetic systems, where Dzyaloshinskii-Moriya (DM) interaction is present. First-principle methods, based on density functional theory (DFT), have been used to study the pairwise magnetic interactions, such as Heisenberg exchange and DM interaction, which are the crucial parameters for the helimagnetic systems. LÄS MER