Modelling of ion deceleration in interpenetrating laser-generated plasma plumes

P Mora,K A Tanaka,R Liska,O Renner,O Larroche,E Dalimier,E Moses

doi:10.1051/epjconf/20135905017

Abstract

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.

Highlights

Plasma-wall interactions (PWI) are important for inertial confinement and magnetic fusion
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
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

Summary

INTRODUCTION

Plasma-wall interactions (PWI) are important for inertial confinement and magnetic fusion. We contribute to the PWI studies by modelling the laser interaction with foils and subsequent interaction of two plasma plumes. The foils are placed parallel at a distance L = 600 m (height z = 800 m and 200 m respectively in following figures). The Al foil is irradiated from above by a laser beam with wavelength = 0.438 nm, energy 115 J, full width at half maximum (FWHM) pulse length 300 ps, and focal spot radius 40 m. The Mg foil is irradiated from below by a weaker laser (energy 6 J, FWHM 300 ps, focal spot radius 25 m)

PRINCIPLES OF HYDRODYNAMICAL SIMULATIONS

DISCUSSION

CONCLUSION