Sökning: "magnetic reconnection"
Visar resultat 6 - 10 av 24 avhandlingar innehållade orden magnetic reconnection.
6. Electron energization in near-Earth space : Studies of kinetic scales using multi-spacecraft data
Sammanfattning : Plasma, a gas of charged particles exhibiting collective behavior, is everywhere in the Universe. The heating of plasma to millions of degrees and acceleration of charged particles to very high energies has been observed in many astrophysical environments. How and where the heating and acceleration occur is in many cases unclear. LÄS MER
7. Energy Conversion and Particle Acceleration at Turbulent Plasma Jet Fronts
Sammanfattning : High-speed plasma flows (jets) are ubiquitous phenomena in the visible Universe. When the fast plasma flow encounters the ambient plasma at rest, it forms a front where its kinetic energy is dissipated. At the jet front, charged particles gain energy from the electromagnetic fields through heating and acceleration. LÄS MER
8. The diagnostic potential of the He I D3 spectral line in the solar atmosphere
Sammanfattning : The research question of my PhD is in a way a simple one: what can observations of the He I D3 line teach us about the solar chromosphere? This optical spectral line at 5876 Å is generally formed in the upper chromosphere, and is sensitive to the local magnetic field. The He I D3 line is also indirectly sensitive to heating of the transition region and corona, since it is resulting from a transition that occurs between levels in the triplet system of neutral helium. LÄS MER
9. Global Magnetospheric Plasma Convection
Sammanfattning : This thesis deals with the global aspects of plasmaconvection in the magnetosphere as measured by the low-altitudepolar orbiting Astrid-2 and FAST satellites. The major focus ison the electric field measurements, but they are alsocomplemented by magnetic field, ion and electron particle data,which is fundamental for the understanding of theelectrodynamics of the high-latitude auroral ovals and polarcap, which are the regions analysed here. LÄS MER
10. A multiwavelength approach to solar chromospheric heating : New insights from the millimeter continuum
Sammanfattning : The chromosphere is an intermediate layer of the Sun's atmosphere where radiative equilibrium breaks down. The standard chromospheric diagnostics such as the Mg II h and k and Ca II H and K spectral lines are formed under nonlocal thermodynamic equilibrium (NLTE) and they are only partially sensitive to the local conditions. LÄS MER
