Preliminary experiment at LULI toward shock ignition feasibility

Shock ignition is a novel scheme to assemble and ignite thermonuclear fuel. In this scheme, the assembled fuel is separately ignited by a strong, spherical shock driven by the high intensity spike at the end of the laser pulse. In this context, we have performed an experiment on LULI2000 laser facility using a simpler geometry to investigate the possibility of generating high shock pressure in large plasma. This experiment required two beams: the first one (I$\sim $ 5x10$^{13}$ W/cm$^{2}$ at 2w) to launch a shock on a planar target and consequently a long plasma on the front side, the second one (I$\sim $10$^{15}$ W/cm$^{2}$ at 2w) for the spike. In this presentation, we report the first results concerning: (i) the measurement of the laser backscattered energy via stimulated Brillouin and Raman ; (ii) the characterization of the shocks (velocity and temperature).