Modelling of ion deceleration in interpenetrating laser-generated plasma plumes

The modelling of intense laser interaction with solid targets represents a complicated complex of plasma physics and numerical methods. The presented simulations contribute to a better understanding of plasma-wall interactions by studying the interpenetration and mutual deceleration of two plasma plumes of different materials created on two foil targets. The initial phase is simulated by the 2D hydrodynamics code PALE until the plumes start to interpenetrate. The mixing, interpenetration and deceleration of the plumes cannot be modelled by standard hydrodynamic methods and a more advanced model has to be used. We employ the 1.5D multi-fluid code MULTIF which is designed for modelling of mixing, interpenetration and deceleration of several plasmas from different materials. The simulated velocity profiles of the Al ions reveal oscillations due to their deceleration and reflection. Those numerical results compare well with X-ray spectroscopic measurements performed at the PALS laser facility. (authors)