Reduced reshock growth in a convergent/divergent system: Effect of reshock strength

The Richtmyer-Meshkov instability creates or seeds hydrodynamic instabilities that will mix cold shell material into the hot DT fuel in an ignition capsule and may prevent ignition. Characteristic of this process is multiple shocks crossing converging interfaces. To mimic this situation, strong converging shocks were created, passed over an unstable interface, reflected by an inner cylinder, and then reshocked the interface. Analysis of the mix width at the unstable surface shows no additional growth, within experimental uncertainty, due to an initially perturbed surface and no dependence on reshock strength

Mass distribution of hydrodynamic jets produced on the national ignition facility

The production of supersonic jets of material via the interaction of a strong shock wave with a spatially localized density perturbation is a common feature of inertial confinement fusion and astrophysics. The spatial structure and mass evolution of supersonic jets has previously been investigated in detail [J. M. Foster et. al, Phys. Plasmas 9, 2251 (2002) and B. E. Blue et. al, Phys. Plasmas 12, 056312 (2005)]. In this paper, the results from the first series of hydrodynamic experiments will be presented in which the mass distribution within the jet was quantified. In these experiments, two of the first four beams of NIF are used to drive a 40 Mbar shock wave into millimeter scale aluminum targets backed by 100 mg/cc carbon aerogel foam. The remaining beams are delayed in time and are used to provide a point-projection x-ray backlighter source for diagnosing the structure of the jet. Comparisons between data and simulations using several codes are presented

Measurements of gas filled halfraum energetics at the national ignition facility using a single quad

Gas filled halfraum experiments were conducted at the National Ignition Facility which provided an excellent test of the tools needed to understand halfraum energetics in an ignition relevant regime. The experiments used a highly shaped laser pulse and measured large levels of backscattered laser energy. These two components challenge the ability of radiation hydrodynamic simulations to model the experiments. The results show good agreement between experimental measurements and simulations