Sökning: "Bernstein waves"

Hittade 4 avhandlingar innehållade orden Bernstein waves.

  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

  3. 2. A Simulation Approach to Plasma Waves

    Författare :Etienne Koen; Tomas Karlsson; Ioannis Kourakis; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Electrostatic waves in the form of Broadband Electrostatic Noise (BEN) have been observed inthe Earth’s auroral region associated with high geomagnetic activity. Their broad frequencyspectrum consists of three electrostatic modes, namely electron plasma, electron acoustic andbeam-driven modes. LÄS MER

  4. 3. Cluster Observations and Theoretical Explanations of Broadband Waves in the Auroral Region

    Författare :Marie Backrud; Jan-Erik Wahlund; Mats André; David Knudsen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Space and plasma physics; ion acoustic waves; auroral region; anomalous resistivity; Cluster; Rymd- och plasmafysik; Space physics; Rymdfysik;

    Sammanfattning : Broadband extremely low-frequency wave emissions below the ion plasma frequency have been observed by a number of spacecraft and rockets on auroral field lines. The importance of these broadband emissions for transverse ion heating and electron acceleration in the auroral regions is now reasonably well established. LÄS MER

  5. 4. Modeling RF waves in hot plasmas using the finite element method and wavelet decomposition : Theory and applications for ion cyclotron resonance heating in toroidal plasmas

    Författare :Pablo Vallejos; Thomas Jonsson; Torbjörn Hellsten; Philippe Lamalle; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : Fusion energy has the potential to provide a sustainable solution for generating large quantities of clean energy for human societies. The tokamak fusion reactor is a toroidal device where the hot ionized fuel (plasma) is confined by magnetic fields. Several heating systems are used in order to reach fusion relevant temperatures. LÄS MER