Sökning: "ion velocity"

Visar resultat 6 - 10 av 63 avhandlingar innehållade orden ion velocity.

  1. 6. 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. 7. Light-Matter Interaction and Quantum Computing in Rare-Earth-Ion-Doped Crystals

    Författare :Adam Kinos; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Rare-Earth-Ion-Doped Crystals; Quantum Computing; Light-Matter Interaction; Fysicumarkivet A:2018:Kinos;

    Sammanfattning : In this thesis, crystals of yttrium orthosilicate (Y2SiO5) that are randomly doped with another rare-earth element, such as praseodymium (Pr), europium (Eu), or cerium (Ce), are investigated with lasers locked to ultra-stable cavities using the Pound-Drever-Hall locking technique. Many of these rare-earth elements have long-lived 4f-4f transitions, hundreds of microseconds to a few milliseconds, with even longer ground hyperfine lifetimes of up to several days. LÄS MER

  3. 8. Theoretical and experimental studies of the flux-flow type Josephson oscillator

    Författare :Yongming Zhang; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nb NbOx PbBi tunnel junction; resistive loading; effect of self-field; resonant fluxion motion; velocity-matching step; chaotic phenomena; SIS detector; optimum bias feed; uniform bias feed; open-circuit boundary condition; perturbed sine-Gordon qeuation; reactive ion beam oxidation; effect of damping; one dimensional Josephson junction; flux-flow type Josephson oscillator;

    Sammanfattning : .... LÄS MER

  4. 9. High altitude ion heating observed by the Cluster spacecraft

    Författare :Martin Waara; Hans Nilsson; Kristina Lynch; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Space physics; Rymdfysik; rymd- och plasmafysik; Space and Plasma Physics;

    Sammanfattning : This thesis deals with heating of outowing oxygen ions at high altitude above the polar cap using data from the Cluster spacecraft. oInospheric plasma may flow up from the ionosphere but at velocities which are low enough that the ions are still gravitationally bound. For the ions to overcome gravity, further acceleration is needed. LÄS MER

  5. 10. Quantum memory development and new slow light applications in rare-earth-ion-doped crystals

    Författare :Qian Li; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Quantum memories; Slow light; Rare-earth-ion-doped crystals; Light-Matter Interaction; Fysicumarkivet A:2018:Li;

    Sammanfattning : When doped into solid state transparent crystals, rare-earth ions can have optically excited states with milliseconds coherence time and up to six hours coherence time for hyperfine levels after being cooled down to liquid helium temperature. This long coherence property makes them unique as solid state material and attractive for quantum information applications. LÄS MER