Experimental evidence of a bubble-merger regime for the Rayleigh-Taylor Instability at the ablation front. (May 2016)

• Record Type: Journal Article
• Authors: Casner, A; Liberatore, S; Masse, L; Martinez, D; Haan, S W; Kane, J; Moore, A S; Seugling, R; Farrell, M; Giraldez, E; Nikroo, A; Smalyuk, V A; Remington, B A
• Is Part Of: Journal of physics. Volume 717(2016)
• Publication Date: 2016-05
• Subjects: Physics -- Congresses; 530.5
• DOI: 10.1088/1742-6596/717/1/012010
• Languages: English
• ISSNs: 1742-6588

Abstract

Abstract: Under the Discovery Science program, the longer pulses and higher laser energies provided by the National Ignition Facility (NIF) have been harnessed to study, first time in indirect-drive, the highly nonlinear stage of the Rayleigh-Taylor Instability (RTI) at the ablation front. A planar plastic package with pre-imposed two-dimensional broadband modulations is accelerated for up to 12 ns by the x-ray drive of a gas-filled gold radiation cavity with a radiative temperature plateau at 175 eV. This extended tailored drive allows a distance traveled in excess of 1 mm for a 130 μ m thick foil, a factor 3x larger than previously achieved on other laser facilities. As a consequence, we have measured the ablative RTI in transition from the weakly nonlinear stage up to the deep nonlinear stage for various initial conditions. A bubble merger regime has been observed and the ablative stabilization strength varied by changing the plastic dopant from iodine to germanium.