Electromagnetic Radiation from Relativistic Electrons as Characteristic Signature of their Dynamics

This Diploma thesis summarizes the development, verification and application of three different parallel codes for computing electromagnetic fields generated by particles moving at relativistic velocities. The codes are based on the classical Liénard-Wiechert potential formalism. Highly efficient numerical solutions for modeling the radiation emitted by millions to billions of particles are introduced and implemented for parallel compute architectures. The first code allows to simulate the electromagnetic near and far field at arbitrary spatial and temporal resolution. The numerical solution of the Liénard-Wiechert potentials in the time domain used in this code is especially suited to compute strongly varying electromagnetic fields in space and time as they occur in coherent synchrotron radiation. The second code computes the angularly resolved radiation spectrum emitted in the far field. It simply requires electron trajectories as provided by many particle simulations as an input. Due to its open structure its applications ranges from determining the beam emittance of an electron beam via Thomson scattering to predicting radiation produced in laser-plasma interactions. It is however limited by file system size and bandwidth and cannot be applied to large-scale plasma simulations. Large-scale plasma simulations are the domain of the third code. Similarly to the second code it computes the radiation intensity per unit solid angle and unit frequency. The code is implemented for use on graphics processing units (GPUs) and integrated into the particle in cell code PIConGPU. It thus provides a highly-efficient, strongly-scalable method to compute the complete radiation spectrum emitted over the full solid angle by all particles in a laser plasma simulation. The range of frequencies spans from the infrared to the X-ray region. This allows to directly links spectral signatures to specific plasma dynamics such as electron injection and betatron oscillations occurring in laser wakefield acceleration. Such spectra can be compared to experimental measurements and can thus help to better understand the femtosecond particle dynamics in laser plasma interactions.Diploma Thesis for the acquisition of the academic degree Diplom-Physike