München 2019 – wissenschaftliches Programm
P 8.5: Vortrag
Dienstag, 19. März 2019, 12:00–12:15, HS 20
Investigation of Plasma Expansion on Solid Surfaces Interacting with an Ultrashort Laser Pulse in the Weakly-Relativistic Intensity Regime — •Steffen Mittelmann1, Götz Lehmann2, Georg Pretzler1, and Michael Stumpf1 — 1Institut für Laser- und Plasmaphysik, Heinrich-Heine-Universität Düsseldorf — 2Institut für Theoretische Physik I, Heinrich-Heine-Universität Düsseldorf
The dynamics of plasma generation and expansion of a solid surface irradiated by a few-fs, ultra-high contrast weakly-relativistic laser pulse is studied by particle-in-cell simulations. The aim is to observe the onset and the dynamics of plasma expansion on a time-scale less than 100 fs after the main interaction, which is a challenging regime for experimental observations. These dynamics have been previously investigated in the PHASER (Phase-Stabilized Heine Laser) lab in Düsseldorf. A pump-probe experiment was used to detect a spatially structured plasma expansion. Our investigations are made with the simulation code EPOCH and give insight into a potential origin of the observed structured expansion. We are able to identify the plasma behaviour investigated in the experiment and we can show that an important role is attributed to the fact that the used target is a layered system of aluminium coated on a fused quartz substrate.