Sökning: "magnetohydrodynamic"

Visar resultat 16 - 20 av 26 avhandlingar innehållade ordet magnetohydrodynamic.

1. 16. The synthetic chromosphere : Results and techniques with a numerical approach

   Författare :Johan Pires Bjørgen; Jorrit Leenaarts; Oskar Steiner; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sun; chromosphere; radiative transfer; numerical method; Astronomy; astronomi;

   Sammanfattning : Realistic numerical simulations of the solar atmosphere can be used to interpret different phenomena observed on the solar surface. To gain insight into the atmospheric physical conditions, we compare the observations with 3D radiative magnetohydrodynamic models combined with forward modeling (radiative transfer). LÄS MER

3. 17. Multi-point Measurements of Ultra Low Frequency Waves in the Terrestrial Magnetosphere

   Författare :Tommy Eriksson; Lars Blomberg; Ian Mann; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Space physics; Rymdfysik;

   Sammanfattning : Waves in the mHz frequency range are prominent features of the terrestrial magnetosphere. In this frequency range the waves have wavelengths comparable to the lengths of the geomagnetic field lines. The waves are then standing waves along closed field lines with endpoints in the southern and northern ionosphere. LÄS MER

4. 18. Resonant Waves in the Terrestrial Magnetosphere

   Författare :Tommy Eriksson; Lars Blomberg; Stephan Buchert; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Space physics; Rymdfysik;

   Sammanfattning : Waves in the mHz frequency range are a prominent feature in the terrestrial magnetosphere. In this frequency range the waves have wavelengths comparable to the lengths of the geomagnetic field lines. The waves are then standing waves along closed field lines with endpoints in the southern and northern ionosphere. LÄS MER

5. 19. Coupling and Absorption of Lower Hybrid Waves in Current Profile Control Experiments in the JET Tokamak

   Författare :Annika Ekedahl; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : Current drive with radio frequency waves in the lower hybrid frequency range is an important method of current profile control via non-inductive current drive in tokamaks. This thesis is concerned with profile control experiments, carried out with the lower hybrid current drive system in the Joint European Torus (JET) tokamak, with the aim to explore scenarios for operation in high confinement regimes with peaked pressure profiles. LÄS MER

7. 20. Generation of magnetic fields in plasmas

   Författare :Nitin Shukla; Gert Brodin; Dusan Jovanovic; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Relativistic and non-relativistic plasma outflows are quite ubiquitous in astrophysical scenarios, as well as in laboratory plasmas. The propagation of relativistic and non- relativistic charged particle beams in background plasmas provides return currents in the opposite direction and interactions between the currents then drive several plasma instabilities involving the longitudinal (electrostatic instabilities) and trans- verse (electromagnetic instability) modes. LÄS MER