Collisionless shock formation and particle acceleration in conditions relevant for NIF experiments

Collisionless shocks are ubiquitous in the Universe and play an important role in the slow down of plasma flows, magnetic field generation/amplification, and particle acceleration. Depending on the plasma conditions, different plasma processes are believed to mediate shock formation and particle injection, however, these are not yet fully understood. Kinetic plasma simulations and high-energy-density (HED) laser-plasma experiments can help probe different plasma conditions and identify the dominant processes. We will present recent particle-in-cell (PIC) simulations of counter-streaming plasma flows for conditions relevant to ongoing collisionless shock experiments at the National Ignition Facility (NIF). The simulations take into account the time-dependent density and velocity profiles of the flows, that are inferred from hydrodynamical simulations. We will discuss the signatures of shock formation, the onset of particle acceleration, and the role of collisional effects. Finally, we will compare the simulations with the some of the first experimental results from NIF.