Sökning: "relativistic particles"

Visar resultat 16 - 20 av 38 avhandlingar innehållade orden relativistic particles.

  1. 16. Generation of magnetic fields in plasmas

    Författare :Nitin Shukla; Gert Brodin; Dusan Jovanovic; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Relativistic and non-relativistic plasma outflows are quite ubiquitous in astrophysical scenarios, as well as in laboratory plasmas. The propagation of relativistic and non- relativistic charged particle beams in background plasmas provides return currents in the opposite direction and interactions between the currents then drive several plasma instabilities involving the longitudinal (electrostatic instabilities) and trans- verse (electromagnetic instability) modes. LÄS MER

  2. 17. Cosmological models, nonideal fluids and viscous forces in general relativity

    Författare :Daniele Gregoris; Kjell Rosquist; Alan Coley; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; gravity; exact model; black hole; friction; teoretisk fysik; Theoretical Physics;

    Sammanfattning : This thesis addresses the open questions of providing a cosmological model describing an accelerated expanding Universe without violating the energy conditions or a model that contributes to the physical interpretation of the dark energy. The former case is analyzed considering a closed model based on a regular lattice of black holes using the Einstein equation in vacuum. LÄS MER

  3. 18. Modelling of laser plasma interaction with applications to particle acceleration and radiation generation

    Författare :Benjamin Svedung Wettervik; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; plasma; ion acceleration; continuum methods; electron wakefield acceleration; raditation generation; coherent X-ray pulses; Vlasov-Maxwell equations;

    Sammanfattning : The development of laser systems with ultra-high intensities has allowed the study of the relativistic interaction of laser light and ionized matter, plasmas, as well as opened up prospects for compact particle accelerators, generation of high intensity X-ray, XUV radiation, and probing QED-effects, which are present in the high intensity regime. To describe laser matter interaction, it is necessary to self-consistently account for the paths of a large number of particles and the corresponding electromagnetic fields, with the addition of stochastic effects at high laser intensities. LÄS MER

  4. 19. Modelling of laser plasma interaction with applications

    Författare :Benjamin Svedung Wettervik; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; electron wakefield acceleration; ion acceleration; coherent X-ray pulses; plasma; Vlasov-Maxwell equations; continuum methods; radiation generation;

    Sammanfattning : The development of laser systems with ultra-high intensities has both opened up prospects for compact particle accelerators, as well as probing QED-effects, which are present in the high intensity regime. To describe laser matter interaction, it is necessary to self-consistently account for the paths of a large number of particles and the corresponding electromagnetic fields, with the addition of stochastic effects at high laser intensities. LÄS MER

  5. 20. Pushing methods for plasma simulations into the QED regime

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

    Sammanfattning : The interaction between a super-intense laser pulse, with intensity up to 10²² W/cm², and a plasma opens new regimes of physics, with new questions and more demand on existing numerical tools. Relativistic and quantum effects which are negligible for lower laser intensities become important and must be properly modelled to generate reliable predictions. LÄS MER