Studies on shock ignition targets for inertial fusion energy

Shock-ignited inertial fusion targets are studied by one dimensional and two-dimensional numerical simulations. Most of the study refers to the simple all-DT HiPER baseline target (imploded mass of 0.29 mg); both the reference laser wavelength λ = 0.35 μm, and λ = 0.25 μm are considered. The target achieves 1D gain about 80 (120) with total laser energy of 260 kJ (180 kJ) at λ = 0.35 μm (0.25 μm). Operating windows for the parameters of the laser ignition spike are described. According to preliminary simulations, gain 80-100 is also obtained by a scaled target (imploded mass of 1.8 mg) driven by 1.5 MJ of green laser light (0.53 μm). Two dimensional simulations indicate robustness to irradiation nonuniformities, and high sensitivity to target mispositioning. This can however be reduced by increasing the power of the ignition spike.