Pushing methods for plasma simulations into the QED regime

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. Increased laser intensity opens up previously unexplored or unattainable regimes and allows for the study of basic physical phenomenon, such as when energy loss through radiation starts to have large effects on particle dynamics. In this thesis we develop schemes to include high intensity radiation from relativistic particles in classical particle-in-cell plasma simulations, with the corresponding energy loss from classical electrodynamics as well as quantum electrodynamic theory. We examine the effect of properly modelling radiation energy losses for laser wakefield acceleration. We propose a novel, tunable scheme for generation of X-ray radiation through interacting laser wakefields, while also finding a regime with strong and stable electron bunch oscillations. We examine the difference between classical and quantum theory in the collision between a laser pulse and an electron, proposing experimental signatures for detection of effects of quantum radiation reaction, a stochastic effect of energy loss through radiation. Furthermore, we use the Manley-Rowe relations to verify the form of a term in the  quations for quantum hydrodynamics.