Sökning: "Acceleration"

Visar resultat 1 - 5 av 438 avhandlingar innehållade ordet Acceleration.

  1. 1. Extreme Electron Beams and Brilliant X-rays : Generation, Manipulation and Characterization of Relativistic Electron Beams for and from Plasma-Based Accelerators

    Författare :Jonas Björklund Svensson; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; laser; plasma; wakefield; acceleration; accelerator; relativistic; electrons; x-rays; ultra-fast; betatron; laser-wakefield acceleration; plasma-wakefield acceleration;

    Sammanfattning : This thesis is based on work done by the author on the development of plasma-based electron accelerators driven by ultra-intense laser pulses and dense electron bunches. Plasma based accelerators have several benefits, such as accelerating fields around 1000 times stronger than in “conventional” radio-frequency accelerators, which can allow for shrinking the overall footprint of the accelerator. LÄS MER

  2. 2. Applications of Laser-Plasma Acceleration

    Författare :Kristoffer Svendsen; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; laser wakefield acceleration; betatron radiation; X-rays; X-ray imaging; phase-contrast imaging; VHEE; radiotherapy; radiography; fuel injector; tomography; beam focusing; atomizing sprays; nanowires; liquid mass; target normal sheath acceleration; applications; charged particles;

    Sammanfattning : This thesis is dedicated to the investigation of laser-plasma particle acceleration concepts. Some of the work was focused on improving electron and proton acceleration for future applications, in terms of maximizing the particle energy and minimizing the divergence of the X-ray beams. LÄS MER

  3. 3. Laser-Driven Particle Acceleration - Improving Performance Through Smart Target Design

    Författare :Matthias Burza; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; wakefield; ultra-relativistic; ultra-intense; TNSA; Terawatt; sheath; proton; polarimetry; plasma mirror; plasma; Petawatt; particle; oscillation; Normarski; micromachining; LWFA; laser; interferometry; electron; contrast; acceleration; bubble; Fysicumarkivet A:2012:Burza;

    Sammanfattning : Laser-driven particle acceleration makes use of sub-picosecond, pulsed, high-power laser systems, capable of producing intensities ~10^{19} W/cm^2 at the laser focus to form plasmas, and use ultra-relativistic and nonlinear dynamics to produce quasistatic acceleration fields. This allows electrons to be accelerated to ~100 MeV over sub-centimetre distances, while protons may be accelerated to the ~10 MeV regime. LÄS MER

  4. 4. Convergence Acceleration for Flow Problems

    Författare :Henrik Brandén; Sverker Holmgren; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Computational fluid dynamics; convergence acceleration; semicirculant preconditioning; fundamental solutions; Numerical Analysis; Numerisk analys;

    Sammanfattning : Convergence acceleration techniques for the iterative solution of system of equations arising in the discretisations of compressible flow problems governed by the steady state Euler or Navier-Stokes equations is considered. The system of PDE is discretised using a finite difference or finite volume method yielding a large sparse system of equations. LÄS MER

  5. 5. Target and Laser Pulse Optimization for Laser-Driven Ion Acceleration

    Författare :Alexander Permogorov; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Terawatt laser; Target normal sheath acceleration; laser-driven ion acceleration; proton acceleration; double plasma mirror; Thomson parabola spectrometer; Fysicumarkivet A:2021:Permogorov;

    Sammanfattning : The research presented in this thesis is primarily focused on experimental investigations of laser-driven ion acceleration from solid targets via the target normal sheath acceleration mechanism. In particular, ways of optimizing the absorption of the laser pulse energy by free plasma electrons in the target, or modifying the shape of the accelerating electron sheath were addressed. LÄS MER