Fast ignition of imploded fusion targets by laser-driven protons

Proton fast ignition (pFI) is an alternative scheme for igniting thermonuclear fuels with lower laser energy and drive symmetry requirements [Roth et al., PRL 86, 436 (2001)]]. The proton beam characteristics estimated for fast ignition have been based so far on strong assumptions about beam focusing and ideal beam-plasma interaction [J.J. Honrubia and M. Murakami, Phys. Plasmas 22, 012703 (2015)]. We have eliminated some of those assumptions to get a more realistic picture of pFI. We conducted pseudo-integrated simulations of pFI by combining two-dimensional PIC for proton acceleration [EPOCH code; Arber et al., Plasma Phys. Control. Fusion 57, 113001 (2015)], radiation-hydrodynamic for cone-in-shell implosion [FLASH code; Fryxell et al., ApJS 131, 273 (2000)] and charged-particle transport hybrid code for ignition calculations [PETRA code; Honrubia et al., Phys. Plasmas 16, 102701 (2009)]. Magnetic field generation within the cone and the subsequent beam divergence have been mitigated by a special cone design. The goal has been to obtain a realistic estimate of the short-pulse laser energy requirements for high gains. Ignition energies from those realistic simulations will be compared with the ones obtained for the standard ideal proton pulse and DT density distributions. They will give us an idea of the importance of new effects considered in this work. It will help assess the potential of proton-fast ignition as an alternative scheme for Inertial Fusion Energy.