Laser plasma interaction physics on the LIL facility

P E Masson-Laborde ,C Stenz,P Loiseau,W Nazarov,C Labaune,C Goyon,C Riconda,S Hüller,S Depierreux,M Casanova,R Wrobel,J Robiche,D Pesme,Denis Marion ,Vincent Yahia ,Н Г Борисенко ,Ph Nicolaï ,D Teychenné ,D T Michel ,V T Tikhonchuk

doi:10.1051/epjconf/20135905003

Abstract

We present an overview of the interpretation of laser plasma interaction (LPI) experiments carried out on the LIL facility. These multikilojoule experiments have been done using underdense foam targets at 0.351 μm laser light leading to high temperature and large plasmas. We discuss the interpretation using our different numerical tools: hydrodynamics simulations carried out with the code FCI2 to characterize the plasma, linear gain estimates with the postprocessor Piranah and paraxial simulations with the code HERA.

Highlights

In order to understand the behavior of parametric instabilities such as stimulated Brillouin scattering (SBS) or Stimulated Raman scattering (SRS) in conditions relevant to ignition plasmas [1, 2], we need some multikilojoule experiments which can lead to high temperature and large plasmas
We present an overview of the interpretation of laser plasma interaction (LPI) experiments carried out on the LIL facility
In order to prepare the first experiments on the National Ignition Facility (NIF) and to study in more details plasma parameters encountered in indirect drive ignition design, a series of laser-plasma interaction experiments were done on the Omega laser facility [7] and on the NIF Early Light (NEL) laser, the first quad of the NIF between 2005 and 2009

Summary

INTRODUCTION

In order to understand the behavior of parametric instabilities such as stimulated Brillouin scattering (SBS) or Stimulated Raman scattering (SRS) in conditions relevant to ignition plasmas [1, 2], we need some multikilojoule experiments which can lead to high temperature and large plasmas. In order to prepare the first Laser MegaJoule (LMJ) experiments and to validate specific technical choices (such as the implementation of longitudinal smoothing by spectral dispersion (LSSD) as laser beam smoothing techniques), the same approach has to be done This validation step needs to be carried out, as in the Omega or NEL laser facility, for large (millimeter size) and hot plasmas (typically around 2 keV) with large focal spot, which can be achieved using the LIL facility which is a prototype of a quadruplet of the LMJ. Experiments carried out with underdense foams can mimic the propagation of the laser beam along the hohlraum gas and can achieve these high temperature regimes while at the same time give the possibility to study competition between different mechanisms as SBS and SRS and plasma-induced smoothing (PIS)[9] Such plasma conditions can give usefull information for the study of parametric instabilities in the context of shock-ignition scheme [10]

THE LIL EXPERIMENTS

RESULTS AND INTERPRETATION

Stimulated Raman Scattering evolution

CONCLUSION