Godefroy MEYNARD

PhD Student

Resarch activities at CPHT: Theory of Plasmas

Thesis : Control of multi-beam laser-plasma interaction based on optical smoothing combining both temporal and spatial inchoherence
This thesis is co-tutored with the CEA's DPTA laboratory (Department of Theoretical and Applied Physics).
Advisors: Stefan Hüller (CPHT), Gilles Riazuelo (CEA-DPTA), Denis Penninckx (CEA-DPTA)

Research interests: statistical optics, laser inertial confinement fusion, numerical simulations, non linear plasma waves, laser-plasma interaction

Abstract:

The major laser facilities for Inertial Confinement Fusion (ICF) use configurations that bundle groups of laser beams in order to illuminate the ICF target. All the beams used for this purpose are subject to so-called 'optical smoothing' techniques that partially reduce the light coherence, with the goal to better control laser-plasma interaction processes. Because of the high complexity of these interactions, there are numerous processes that can potentially deteriorate the absorption of the laser light in the plasma. The currently used optical smoothing techniques are not sufficiently versatile to avoid the onset of several detrimental processes at the same time, which is due to the various temporal and spatial scales involved.
The goal of the envisaged theoretical-numerical thesis work is to apply new innovative optical smoothing techniques based on both larger laser band width and on laser pulses that use well-controlled sub-pulses. The latter allow us to control the induced fluctuations in the plasma, and eventually to limit considerably the growth of undesirable laser-plasma instabilities.
The envisaged techniques to explore are much more promising than currently available techniques.