Sökning: "plasmas"

Visar resultat 1 - 5 av 211 avhandlingar innehållade ordet plasmas.

  1. 1. Waves in space plasmas : Lower hybrid cavities and simple-pole distribution functions

    Författare :Anders Tjulin; Mats André; Hans Pécseli; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Space and plasma physics; space physics; plasma; waves; dispersion relations; lower hybrid cavities; Cluster; magnetosphere; Rymd- och plasmafysik; Space physics; Rymdfysik;

    Sammanfattning : Waves are a fundamental feature in many parts of physics, since they transport energy without transporting matter. This is the case also in space physics. Waves are responsible for energy transport both between different parts of space and between different particles in the space plasma. LÄS MER

  2. 2. Modelling and measuring transport in fusion plasmas

    Författare :Istvan Pusztai; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; fusion plasmas; ITG stability; microinstabilities; de-convolution; Lorentz operator; gyrokinetic equation; transport; quasilinear flux; beam emission spectroscopy; ion temperature gradient mode; electron density measurement; trapped electron response;

    Sammanfattning : In the present thesis we consider theoretical and experimental aspects of the turbulent transport which is a crucial issue in fusion plasma physics.Experimental observations and gyrokinetic simulations show that collisions strongly influence the turbulent flux of particles. LÄS MER

  3. 3. QED and collective effects in vacuum and plasmas

    Författare :Joakim Lundin; Mattias Marklund; Thomas Heinzl; Umeå universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; QED; quantum electrodynamics; quantum plasmas; quantum vacuum; Plasma physics; Plasmafysik; fysik; Physics;

    Sammanfattning : The theory of quantum electrodynamics (QED) was born out of an attempt to merge Einsteins theory of special relativity and quantum mechanics. Einsteins energy/mass equivalence together with Heisenberg's uncertainty principle allows for particle pairs to be spontaneously created and annihilated in vacuum. LÄS MER

  4. 4. Thermonuclear instabilities and fast particle transport in fusion plasmas

    Författare :Tünde Fülöp; Chalmers University of Technology; []
    Nyckelord :tokamaks; alpha particles; electron beam transport; Toroidal Alfvén Eigenmodes; thermonuclear instabilities; fusion plasmas; Ion Cyclotron Emission;

    Sammanfattning : .... LÄS MER

  5. 5. The Klimontovich description of complex plasma systems : Low frequency electrostatic modes, spectral densities of fluctuations and collision integrals

    Författare :Panagiotis Tolias; Lars Blomberg; Carmine Castaldo; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; complex plasmas; dusty plasmas; Klimontovich equations; kinetic theory; dust acoustic waves; collision integrals;

    Sammanfattning : Plasmas seeded with solid particulates of nanometer to micron sizes (complex plasma systems) are a ubiquitous feature of intergalactic, interstellar and planetary environments but also of plasma processing applications or even fusion devices. Their novel aspects compared with ideal multi-component plasmas stem from (i) the large number of elementary charges residing on the grain surface, (ii) the variability of the charge over mass ratio of the dust component, (iii) the inherent openness and dissipative nature of such systems. LÄS MER