Speaker
Description
Ultra-intense lasers that ionize atoms and accelerate electrons in solids to nearly the speed of light can lead to kinetic instabilities that alter the laser absorption and subsequent electron transport, isochoric heating, and plasma expansion. These instabilities can be difficult to characterize, but a novel approach using X-ray scattering at keV photon energies allows for their visualization with femtosecond temporal resolution on the few nanometer mesoscale. Our experiments on laser-driven flat silicon membranes show the development of such structures on these previous unaccessble scales, which is relevant e.g. for laser particle acceleration, inertial confinement fusion, and laboratory astrophysics.
Combining the XFEL experiments with particle-in-cell (PIC) simulations provides a rich picture of the structural evolution of ultra-fast laser-induced plasma density development, indicating the excitation of plasmons and a filamentation instability. I will briefly introduce the concept of PIC simulations and present results that confirm that the measured signals are due to an oblique two-stream filamentation instability.
Future developments include a combination of several XFEL probe methods, e.g. resonant scattering, imaging, or spectroscopy, that require advancements in modeling the plasma ion excitations in PIC. I will briefly touch on our latest addition of an atomic physics module in PIConGPU that form the basis for such capabilities in the near future.
| Scientific Topic 8 | Beam-plasma and laser-plasma interactions and acceleration |
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