Dynamics of ion heating and ionization in high power ultrashort laser pulses interacting with solid density plasmas

Plasma heating and ionization are important processes during the interaction of high power ultra-short laser pulses with solid density targets. In order to understand the relevant physics, particle-in-cell simulations including collisions and ionization were run to study ion heating dynamics in buried layer targets illuminated by high-intensity, ultra-short laser pulses. Our results show that bulk ions can be heated to above 1keV temperature. When studying the ionization dynamics strong filaments have been observed which depend on preplasma on the target front side, laser pulse duration and intensity. In order to study the evolution of ionization and ion bulk heating in experiment, ultra-bright X-ray free electron lasers - such as the European XFEL - are a very promising and strong tool to resolve the spatial and temporal scales of these processes inside the solid target.