Sökning: "spacecraft wake"

Hittade 5 avhandlingar innehållade orden spacecraft wake.

  1. 1. Plasma environment of an intermediately active comet : Evolution and dynamics observed by ESA's Rosetta spacecraft at 67P/Churyumov-Gerasimenko

    Författare :Elias Odelstad; Anders Eriksson; Andrew Coates; Uppsala universitet; []
    Nyckelord :Rosetta; comet; 67P; RPC-LAP; RPC-MIP; RPC-ICA; RPC-MAG; ROSINA-COPS; Langmuir probe; spacecraft potential; plasma; Churyumov-Gerasimenko; ion composition analyzer; diamagnetic cavity; ion velocity; electron temperature; ion-neutral drag; collisional coupling; wake effects; filamentation; electron cooling; plasma waves; hybrid waves; Bernstein waves; minimum variance; polarization; wavelet; density fluctuations; magnetic field oscillations; drift-cyclotron instability; asymmetric plasma and magnetic field enhancements; Fysik med inriktning mot rymd- och plasmafysik; Physics with specialization in Space and Plasma Physics;

    Sammanfattning : The subject of this thesis is the evolution and dynamics of the plasma environment of a moderately active comet before, during and after its closest approach to the Sun. For over 2 years in 2014-2016, the European Space Agency’s Rosetta spacecraft followed the comet 67P/Churyumov-Gerasimenko at distances typically between a few tens and a few hundred kilometers from the nucleus, the longest and closest inspection of a comet ever made. LÄS MER

  2. 2. Low-Energy Ion Escape from the Terrestrial Polar Regions

    Författare :Erik Engwall; Anders I. Eriksson; Mats André; Thomas Moore; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; space physics; ion outflow; polar wind; auroral upflows; atmospheric escape; magnetotail lobes; spacecraft wake; electric field measurements; Geocosmophysics and plasma physics; Geokosmofysik och plasmafysik; Space and Plasma Physics; rymd- och plasmafysik;

    Sammanfattning : The contemporary terrestrial atmosphere loses matter at a rate of around 100,000 tons per year. A major fraction of the net mass loss is constituted by ions, mainly H+ and O+, which escape from the Earth’s ionosphere in the polar regions. LÄS MER

  3. 3. Plasma Interactions with Icy Bodies in the Solar System

    Författare :Jesper Lindkvist; Mats Holmström; Martin Wieser; Elias Roussos; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; plasma interactions; icy bodies; solar system; space physics; plasma physics; hybrid model; numerical model; solar wind; magnetosphere; sub-Alfvénic; subsonic; non-collisional; atmosphereless; exosphere; coma; subsurface ocean; induction; magnetic dipole; pick-up ion; mass-loading; moon; natural satellite; dwarf planet; comet; Jupiter; Jovian; Callisto; Ceres; 67P; Churyumov-Gerasimenko; rymd- och plasmafysik; Space and Plasma Physics;

    Sammanfattning : Here I study the “plasma interactions with icy bodies in the solar system”, that is, my quest to understand the fundamental processes that govern such interactions. By using numerical modelling combined with in situ observations, one can infer the internal structure of icy bodies and their plasma environments. LÄS MER

  4. 4. Energy Conversion and Particle Acceleration at Turbulent Plasma Jet Fronts

    Författare :Louis Richard; Yuri V. Khotyaintsev; Tomas Karlsson; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : High speed plasma flows (jets) are ubiquitous phenomena in the universe. For example, they carry energy from the most powerful sources (e.g active galactic nucleï AGN) to the medium at rest surrounding them. LÄS MER

  5. 5. Energy Conversion and Particle Acceleration at Turbulent Plasma Jet Fronts

    Författare :Louis Richard; Yuri V. Khotyaintsev; Daniel B. Graham; Andris Vaivads; Emiliya Yordanova; Vassilis Angelopoulos; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Plasma jets; Magnetic reconnection; Particle acceleration; Magnetosphere; Magnetospheric Multiscale; Fysik med inriktning mot rymd- och plasmafysik; Physics with specialization in Space and Plasma Physics;

    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