Sökning: "plasma waves"

Visar resultat 21 - 25 av 98 avhandlingar innehållade orden plasma waves.

1. 21. Nonlinear interaction and propagation of gravitational and electromagnetic waves in plasmas

   Författare :Martin Servin; Gert Brodin; Lennart Stenflo; Demetrios Papadopoulos; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Theoretical physics; general relativity; plasma; gravitational waves; electromagnetic waves; nonlinear; wave interaction; wave propagation; Teoretisk fysik; Physics; Fysik; teoretisk fysik; Theoretical Physics;

   Sammanfattning : Gravitational waves and electromagnetic waves are important as carriers of energy and information. This thesis is devoted to the study of the propagation and interaction of these waves in plasmas, with emphasis on nonlinear effects and applications within astrophysics. LÄS MER

3. 22. 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 :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

4. 23. 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. 24. Radiation in simulations of high intensity laser-matter interaction

   Författare :Erik Karl Wallstén Wallin; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; plasma; nonlinear dynamics; particle-in-cell; Manley-Rowe; radiation reaction; synchrotron radiation;

   Sammanfattning : We consider electromagnetic waves propagating in plasmas, with two main themes covered. First nonlinear plasma theory and wave-wave interaction. Here a wave-wave symmetry, the Manley-Rowe relations, is used as a method of determining the physicality of modified plasma fluid equations. LÄS MER

7. 25. Approaches to particle acceleration in intense laser-matter interaction

   Författare :Joel Magnusson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; particle-in-cell; nonlinear dynamics; laser; plasma; laser-matter interaction; particle acceleration;

   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 acceleration and radiation generation, with applications in materials science, biology and medicine. LÄS MER