Promotionsvortrag Physik: „High-intensity laser-target interactions for applications in laboratory astrophysics“

Ankündigung des Promotionsvortrags von: Herrn Christopher Schönwälder

Collisionless shocks are some of the most powerful accelerators in our universe, believed to ac-count for large parts of the cosmic ray spectrum. However, their formation is still a highly debated topic, to which laboratory experiments can offer invaluable insights into the underlying microphysics. In particular, the role of kinetic plasma instabilities in fundamental plasma processes - such as electron transport, ion acceleration and magnetic field amplification – remain poorly under-stood.

Over the past decades, significant efforts have been made to study plasma instabilities, such as the current-filamentation or Weibel instability in relativistic short-pulse laser interactions. However, the underlying microphysics remain elusive due to the short temporal and small spatial scales involved.

This talk presents the results of an experiment conducted at the SLAC National Accelerator Laboratory that successfully imaged the relativistic laser-plasma interaction for the first time. The images show the development and growth of the current filamentation instability and suggest the importance of ion motion in facilitating the instability growth. These observations are used to benchmark fully kinetic PIC simulations and analytical models, uncovering the intricate details of this instability’s behavior in an asymmetric regime. In summary, our findings provide an unprecedented description of the current-filamentation instability relevant to both laboratory and astro-physical plasmas.

(Vortrag auf Englisch)

Dem Vortrag schließt sich eine Diskussion von 15 Minuten an. Vortrag und Diskussion sind öffentlich. Diesen Verfahrensteilen folgt ein nicht öffentliches Rigorosum von 45 Minuten.