Sökning: "Fysik med inriktning mot rymd- och plasmafysik"

Visar resultat 6 - 10 av 14 avhandlingar innehållade orden Fysik med inriktning mot rymd- och plasmafysik.

  1. 6. Opening New Radio Windows and Bending Twisted Beams

    Författare :Erik Nordblad; Thomas B. Leyser; Kristof Stasiewicz; Vladimir Pavlenko; Paul A. Bernhardt; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Orbital angular momentum; Hall effect; Nonparaxial beam; Geometrical optics; High frequency radio waves; Ray tracing; Magnetic zenith effect; Ionospheric irregularities; Wave propagation; Fysik med inriktning mot rymd- och plasmafysik; Physics with specialization in Space and Plasma Physics;

    Sammanfattning : In ground based high frequency (HF) radio pumping experiments, absorption of ordinary (O) mode pump waves energises the ionospheric plasma, producing optical emissions and other effects. Pump-induced or natural kilometre-scale field-aligned density depletions are believed to play a role in self-focussing phenomena such as the magnetic zenith (MZ) effect, i. LÄS MER

  2. 7. Diving Deep into Saturn's Equatorial Ionosphere with Cassini : Insights from the Grand Finale

    Författare :Joshua Dreyer; Erik Vigren; Michiko Morooka; Jan-Erik Wahlund; Ingo Müller-Wodarg; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Saturn; Cassini; Grand Finale; Ionosphere; Photochemistry; Planetary Rings; Planetary Science; Space Plasma; Space Physics; Fysik med inriktning mot rymd- och plasmafysik; Physics with specialization in Space and Plasma Physics;

    Sammanfattning : In the summer of 2017, the Cassini mission concluded its nearly 13 years orbiting Saturn with a series of daring dives between the rings and the upper reaches of Saturn's atmosphere. This last phase of the mission, called the Grand Finale, revealed a highly variable equatorial ionosphere dominated by a large influx of ring material from Saturn's D ring. LÄS MER

  3. 8. Saturn's dusty equatorial ionosphere from Cassini's Grand Finale observations

    Författare :Joshua Dreyer; Erik Vigren; Lorenz Roth; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Saturn; Cassini; ionosphere; space plasma; planetary science; Fysik med inriktning mot rymd- och plasmafysik; Physics with specialization in Space and Plasma Physics;

    Sammanfattning : The Cassini mission provided unprecedented insights into the Kronian system and revealed many unexpected phenomena relating to dusty plasma environments around Saturn and its rings. Almost 13 years after its arrival, Cassini began a series of 22 orbits which brought it between Saturn's upper atmosphere and the innermost D ring, culminating in a final plunge into Saturn's ionosphere. LÄS MER

  4. 9. Electrostatic turbulence and electron heating in collisionless shocks

    Författare :Ahmad Lalti; Yuri V. Khotyaintsev; Hans Nilsson; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fysik med inriktning mot rymd- och plasmafysik; Physics with specialization in Space and Plasma Physics;

    Sammanfattning : Collisionless shocks are one of the most peculiar phenomena in space where non-linear collective phenomena in the plasma dominate the dynamics. They are believed to be one of the most efficient particle accelerators in the universe, and have internal dynamics that are yet to be fully explored. LÄS MER

  5. 10. Electron energization in near-Earth space : Studies of kinetic scales using multi-spacecraft data

    Författare :Elin Eriksson; Andris Vaivads; Masahiro Hoshino; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; magnetic reconnection; electron acceleration; electron heating; magnetosheath; magnetotail; magnetic nulls; Cluster; Magnetospheric MultiScale; Fysik med inriktning mot rymd- och plasmafysik; Physics with specialization in Space and Plasma Physics;

    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