Progress in the shock-ignition inertial confinement fusion concept

Shock-ignition experiments with peak laser intensities of ∼8 × 1015 W/cm2 were performed. D2 -filled plastic shells were compressed on a low adiabat by 40 of the 60 OMEGA beams. The remaining 20 beams were delayed and tightly focused onto the imploding shell to generate a strong shock. Up to 35% backscattering of laser energy was measured at the highest intensity. Hard x-ray measurements reveal a relatively low hot-electron temperature of ∼40 keV, independent of intensity and spike onset time.