Ion acceleration via plasma turbulence and collisionless shock generation

High-power laser facilities have made unprecedented progress in recent years. With this the laser-matter interaction has entered parameter regimes of interest for laboratory astrophysics. In particular, the interactions of relativistic short intense lasers with matter can generate some high energy density states (HEDS). For example, magnetic turbulent plasmas can be formed while laser produced high current electron beams transport in solid targets via Weibel instability, and high-energy high-current electron and ion beams can be produced while intense laser pulses interact with gas or solid density plasmas. This instability is widely thought to underpin the physics of relativistic outflows in astrophysical objects (e.g., gamma-ray bursts, pulsar winds, active galactic nuclei), especially as the source of the collisionless shock waves responsible for generating nonthermal high-energy particles and radiations. High-power laser plasma experiments can produce unique parameter regimes with high energy density, while numerical simulations can provide a great variety of information of complex and dynamic systems with high performance computers, which may be measured in experiments.
In this project, Weibel-type magnetic turbulence will be modelled by intense laser solid interactions. Previous simulations have been carried out with low spatial resolutions, limited time and limited to 2D geometry, which cannot be compared directly to experimental observation. With our new code, magnetic plasma turbulence will modelled more accurately in 3D, so that direct comparison with experiments could be made. We shall focus on the micro-processes, like Weibel instabilities and two stream instabilities between forward currents of relativistic hot electrons and cold return currents of background electrons under the irradiance of laser pulses under different intensities, and the subsequent development of magnetic turbulence over the time scale of a few tens of picosecond. The temporal evolution and spatial profiles (power law of k spectra) of magnetic fields will be obtained by kinetic PIC simulations.