In dieser Arbeit untersuchen wir die Polarisation des Quantenvakuums im Rahmen von Kollisionen zweier hochintensiver Laserpulse. Die Theorie der Quantenelektrodynamik in starken Feldern postuliert, dass die klassischen Maxwell-Gleichungen im Vakuum in Anwesenheit von Quantenvakuumfluktuationen nichtlineare…
The acceleration of electron bunches reaching GeV energies within a centimeter-scale device exemplifies the remarkable advancements achieved in the field of laser-plasma acceleration. One essential by-product of such acceleration process is the production of highly energetic X-ray photons. In this thesis,…
Plasma wakefield accelerators can be driven either by intense laser pulses (LWFA) or by intense particle beams (PWFA). A third approach that combines the complementary advantages of both types of plasma wakefield accelerator has been established with increasing success over the last decade and is called…
One of the most intriguing physics processes that remain untested is the pure photon electron-positron pair production via quantum-vacuum fluctuations described by the nonlinear Breit-Wheeler theory. These fluctuations generate virtual pairs that can be turned into observable particles by applying strong…
In this dissertation, the experiments are conducted at the Jenaer Titanium: Sapphire 200 Terawatt Laser System (JETi200) located in Jena, Germany. With its excellent temporal contrast, the few-nanometer freestanding target can remain in a solid state for a few picoseconds before the main pulse arrives,…
High power short pulse lasers provide a promising route to study the strong field effects of the quantum vacuum, for example by direct photon–photon scattering in the all-optical regime. Theoretical predictions based on realistic laser parameters achievable today or in the near future predict scattering…
We describe a laser–plasma platform for photon–photon collision experiments to measure fundamental quantum electrodynamic processes. As an example we describe using this platform to attempt to observe the linear Breit–Wheeler process. The platform has been developed using the Gemini laser facility at…
The interaction of light with the quantum-vacuum is predicted to give rise to some of the most fundamental and exotic processes in modern physics, which remain untested in the laboratory to date. Electron–positron pair production from a pure vacuum target, which has yet to be observed experimentally,…
This work explores the experimental observation of the Breit-Wheeler process, first described by Gregory Breit and John A. Wheeler in 1934 [1], where two photons collide to form an electron positron pair from the quantum vacuum. The specific challenge thereby is the low cross section of a few 10e 29…
In this thesis the generation of high order harmonics of ultrashort and high intensity laser pulses from solid density plasmas, so called surface high harmonic generation (SHHG), is studied. With SHHG, a compact source of coherent XUV and X-Ray radiation becomes possible. The results are obtained numerically…
The aim of this work was to develop a new diagnostic method to probe preplasma properties in laser-plasma interaction experiments, using the time-resolved measurement of the laser pulse reflected by the plasma. Its spectral change over time can be attributed to the motion of the critical-density position…
Recently, measurements of few-picosecond (ps, 10 −12 s) pulses of laser-driven protons were realised by the observation of transient opacity in SiO 2 . This ultrafast response could be understood by the formation of self-trapped excitonic states in the material, creating a rapid de-excitation channel…
Multipass high harmonic generation from plasma surfaces is a promising technique to enhance the efficiency of the generation process. In this paper it is shown that there is an optimal distance between two targets where the efficiency is maximized, depending on the laser and plasma parameters. This can…
In this thesis, several plasma wakefield-based flexible undulator/wiggler schemes have been developed for the generation of high-energy radiation. First, the plasma undulator/wiggler field can be generated by injecting a Gaussian laser pulse with a transverse offset/angle or beating several different…
Die Entwicklung von Laser-Plasma getriebenen Beschleunigern (LWFA) ist eine vergleichsweise neue Entwicklung. Durch die enormen Felder, die das Plasma zur Verfügung stellen kann, ist es möglich, ultrakurze und dichte Elektronenpulse über sehr kurze Strecken zu beschleunigen. In dieser Arbeit wird gezeigt,…