Role of Laser Plasma Interaction in the Shock Ignition regime.
Shock ignition (SI) is a promising two-step scheme to Inertial Confinement Fusion (ICF), where a strong shock wave (>300 Mbar) is launched at the end of the compression phase to ignite the fuel, by means of a short intense spike (300-500 ps) at intensities around 1016 W/cm2. The success of the SI concept depends mainly on the coupling of the laser spike with the imploding plasma shell, where an efficient laser absorption is needed, able to produce a strong shock at the ablation layer. The onset of parametric instabilities, including Stimulated Brillouin Scattering (SBS), Stimulated Raman Scattering (SRS) and Two-Plasmon Decay (TPD), can however produce a degradation of laser-plasma coupling, resulting in a strong reflection of light (SBS and SRS). Moreover, TPD and SRS generate electron plasma waves (EPW) that lead to hot electrons (HE) via damping, which, depending on their energy, may affect the shock pressure or preheat the pre-compressed fuel.
Researchers at ILIL laboratory are active in this research field, in collaboration with European, USA and Japanese research groups, and such activity is at the moment supported by the European Eurofusion consortium. In particular, ILIL researchers investigate the processes of interaction of the laser beam with the plasma corona in experimental conditions as close as possible to those envisaged for SI.
The research proposed for this fellowship is mainly experimental, in campaigns devoted to this subject, including the analysis and the interpretation of the data. The work includes the participation to experimental campaigns in international facilities suitable for the scope, as for example PALS (Prague), CLF (UK) or Gekko (Japan).
For information: Dr. Gabriele Cristoforetti – 0503152222