Shock-Free Acceleration of Laser Driven Targets

The ability of recently developed laser smoothing techniques to produce uniform ablation pressures is strongly contingent on the degree of thermal smoothing. Thermal smoothing is not effective at reducing residual laser nonuniformities during the start up phase of a shaped, reactor-like laser pulse. The impact of the first shock can be diminished by adiabatically compressing the target with a temporally long, slowly rising laser pulse. This Memorandum Report discusses an elastic-plastic laser-matter-interaction model and shows that a shock-free, induced spatial incoherence-smoothed laser pulse can accelerate a target to nearly the conditions required for uniform implosion.