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Visar resultat 1 - 5 av 408 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Solitary waves and enhanced incoherent scatter ion lines

    Författare :Jonas Ekeberg; Lars Eliasson; Kristof Stasiewicz; Jan Trulsen; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; plasma waves and instabilities; nonlinear phenomena; solitons and solitary waves; ionosphere; Sun: corona; incoherent scatter radar; MHD; plasmavågor och instabiliteter; ickelinjära fenomen; solitoner och solitära vågor; jonosfär; solen: korona; inkoherent spridningsradar; MHD; Geocosmophysics and plasma physics; Geokosmofysik och plasmafysik; Space physics; Rymdfysik; Plasma physics; Plasmafysik; Non-linear dynamics; chaos; Icke-linjär dynamik; kaos; fysik; Physics; rymd- och plasmafysik; Space and Plasma Physics;

    Sammanfattning : This thesis addresses solitary waves and their significance for auroral particle acceleration, coronal heating and incoherent scatter radar spectra. Solitary waves are formed due to a balance of nonlinear and dispersive effects. LÄS MER

  2. 2. Space Plasma Dynamics : Instabilities, Coherent Vortices and Covariant Parametrization

    Författare :David Sundkvist; Jan-Erik Wahlund; Andris Vaivads; Stuart Bale; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Space and plasma physics; space physics; plasma; instabilities; turbulence; coherent structures; vortex; self-organization; magnetosphere; waves; electromagnetism; covariant; space instrumentation; Rymd- och plasmafysik; Space physics; Rymdfysik;

    Sammanfattning : The magnetospheric cusps are two funnel-like regions of Earth's magnetosphere where solar wind plasma can have direct access to the ionosphere. The cusps are very dynamic regions where wave-particle interactions continuously take place and redistribute energy among different particle populations. LÄS MER

  3. 3. Plasma properties in high power impulse magnetron sputtering

    Författare :Daniel Lundin; Ulf Helmersson; Jon Tomas Gudmundsson; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; HiPIMS; HPPMS; plasma; plasma transport; plasma instabilities; Plasma physics; Plasmafysik;

    Sammanfattning : The work presented in this thesis involves experimental and theoretical studies related to plasma properties in high power impulse magnetron sputtering (HiPIMS), and more specifically plasma transport. HiPIMS is an ionized PVD method based on conventional direct current magnetron sputtering (dcMS). LÄS MER

  4. 4. Rosetta Observations of Plasma and Dust at Comet 67P

    Författare :Fredrik Leffe Johansson; Anders Eriksson; Jan-Erik Wahlund; Nicolas André; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Rosetta; Comets; Plasma; Langmuir Probes; Dust; Spacecraft-plasma interaction; Electrostatic Probes; Rosetta; kometer; plasma; stoft; rymdfarkost-plasma växelverkan; Fysik med inriktning mot rymd- och plasmafysik; Physics with specialization in Space and Plasma Physics;

    Sammanfattning : In-situ observations of cometary plasma are not made because they are easy. The historic ESA Rosetta mission was launched in 2004 and traversed space for ten years before arriving at comet 67P/Churyumov-Gerasimenko, which it studied in unprecedented detail for two years. LÄS MER

  5. 5. Intense laser-plasma interactions

    Författare :Joel Magnusson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; radiation reaction; radiation generation; particle-in-cell; plasma; pair production cascades; ion acceleration; laser;

    Sammanfattning : In the interaction of ultra-intense laser fields with matter, the target is rapidly ionized and a plasma is formed. The ability of a plasma to sustain acceleration gradients, orders of magnitude larger than achievable with conventional accelerators, has led to a great interest in laser-driven plasma-based particle and radiation sources, with applications in materials science, biology and medicine. LÄS MER