Increased nuclear energy yields from the fast implosion of cold shells driven by nonlinear laser plasma interactions

The nonlinear interaction force between intense laser fields and cold plasma shells efficiently transforms radiant energy into mechanical energy of implosion. This transfer of energy has been considered before in numerical experiments and it is treated here analytically in a didactic example starting with an inhomogeneous Rayleigh density profile. Up to 50% of the laser energy can be transformed into the energy of compression if a single "untailored" pulse of 2.5×10¹⁶ W/cm² intensity and of only a few picosecond duration is used for spherical illumination of a shell. If the pulse is short enough to reduce collisiona) thermalization, then the collapse and compression of the plasma can remain at the threshold of Fermi degeneracy and still be adiabatic. This results in nuclear reaction gains G, based on the deposited energy, E₀, and without a-particle reheating, of G = 400 for E₀ = 2.25 kJ (D–T reaction), 900 kJ (D–D), 13 MJ (H–B). About 1000 times less laser energy is necessary than in the case of gas dynamic ablation resulting in the same nuclear reaction yields.