Supersonic radiation wave in doped low density foam

Abstract

Supersonic heat (Marshak) waves are radiation dominated, and play an important role in inertial confinement fusion and in astrophysical and laboratory systems. Doping the foam with heavy metals with high opacity cause dramatic changing of the heat wave behavior by the changing of the material opacity. For that reason, the effects of doping on heat waves propagation in low density foams have been measured in a number of experiments reported in the literature. The present study uses the NIF facility advantages to overcome the two main problems that have been identified in earlier works: the radiation pre-heat; and the considerable experimental uncertainties in respect to the physical phenomena. The new experiment will be able to measure the coupling between opacity and the heat wave progress and evolution, because the heat wave progress in a doped foam is expected to be very similar to the heat wave progress in the pure foam, when the latter’s absorption cross-section is simply scale by multiplying with a constant factor.