Sökning: "Wakefield"

Visar resultat 11 - 15 av 15 avhandlingar innehållade ordet Wakefield.

1. 11. Laser-Produced Plasmas for Particle Acceleration

   Författare :Kristoffer Svensson; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : This thesis describes experimental studies that aim to stabilise and optimise laser-based particle accelerators. The technique is called laser wakefield acceleration, where electric fields of the order of 102 GV/m accelerate electrons to high energies (⇠102 MeV) over mm-distances in laser-produced plasmas. LÄS MER

3. 12. 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

4. 13. Microphysical Conditioning of Gamma-Ray Burst Shocks

   Författare :Jacob Trier Frederiksen; Claes Fransson; Åke Nordlund; Mikhail V. Medvedev; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; magnetic fields; particle acceleration; plasma instabilities; gamma-ray bursts; collisionless shocks; relativistic outflows; Astronomy and astrophysics; Astronomi och astrofysik; Astronomy; astronomi;

   Sammanfattning : Gamma-Ray Bursts (GRBs) are believed to be connected with either collapse of massive stars or – in some cases – coalescing neutron stars, both of which cause extreme relativistic explosions observable from the entire Universe. GRBs produce rapid flashes of high energy radiation, extending up to 2MeV in photon energies: as much energy per photon as the rest mass of 4 electrons. LÄS MER

5. 14. Experiments on Laser-Based Particle Acceleration : Beams of Energetic Electrons and Protons

   Författare :Kristoffer Svensson; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; laser; plasma; acceleration; electrons; protons; Fysicumarkivet A:2016:Svensson;

   Sammanfattning : This thesis describes experiments involving laser-plasma-based acceleration of electrons and protons, using the techniques of laser wakefield acceleration (LWFA) and target normal sheath acceleration (TNSA). By using extremely high accelerating field strengths, up to the order of TV m-1, it is possible to reach high kinetic particle energies over very short distances. LÄS MER

7. 15. Impedance and Instabilities in the MAX IV 3 GeV Ring

   Författare :Galina Skripka; Lunds universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Collective effects; geometric impedance; resistive wall impedance; wakefields; particle tracking; harmonic cavity;

   Sammanfattning : To ensure the beam with an ultralow emittance and high current the possible effects deteriorating the beam stability must be investigated. When ultrarelativistic particles travel in the vacuum chamber they induce electromagnetic fields which can act back on them and the following particles. LÄS MER