Sprecher
Beschreibung
X-ray sources are of growing importance as a diagnostic tool for fundamental research in High Energy Density (HED) physics and Inertial Confinement Fusion (ICF) studies. These applications deploy so-called x-ray backlighters to probe the interior of the plasma, which should ideally have a low divergence, small source size, to achieve a sufficient imaging resolution, and high brightness to overcome x-ray self-emission from the plasma itself. X-ray sources from laser-driven electrons from the regime of self-modulated laser wakefield acceleration (SM-LWFA) show promising parameters to meet these requirements, which can be achieved by using gas targets and picosecond laser pulses.
To develop such an x-ray source for experiments at the GSI Helmholtzzentrum für Schwerionenforschung, first experiments were conducted in March 2025 using laser pulse durations of 500 fs and intensities up to 1.5e19 W/cm^2. As the gas density distribution plays a crucial role in electron acceleration, the helium profile was characterized using a Mach-Zehnder interferometer.
Based on the experimentally obtained parameters, PIC simulations were performed with WarpX to study electron charge and divergence and to compare the results with the experimental data. These simulations will be further extended to include betatron radiation using PIConGPU. Additionally, the influence of the target density distribution on achieving high charge and low divergence will be investigated by varying the density profiles and gradients.
