Hydrodynamic instability measurements in DT-layered ICF capsules using the layered-HGR platform

9th International Conference on Inertial Fusion Sciences and Applications

Weber, C.^1 ; Döppner, T.^1 ; Casey, D.^1 ; Bunn, T.^1 ; Carlson, L.^2 ; Dylla-Spears, R.^1 ; Kozioziemski, B.^1 ; Macphee, A.G.^1 ; Sater, J.^1 ; Nikroo, A.^1,2 ; Robey, H.^1 ; Smalyuk, V.^1

Lawrence Livermore National Laboratory, Livermore

CA, United States^1

General Atomics, San Diego

CA, United States^2

关键词: Ablation fronts;    Deuterium-tritium fuels;    Hydrodynamic instabilities;    Instability growth;    Instability measurements;    Measurements of;    National ignition facility;    Rayleigh-Taylor growth;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/717/1/012057/pdf
DOI  :  10.1088/1742-6596/717/1/012057

来源: IOP

【 摘 要 】

The first measurements of hydrodynamic instability growth at the fuel-ablator interface in an ICF implosion are reported. Previous instability measurements on the National Ignition Facility have used plastic capsules to measure ablation front Rayleigh-Taylor growth with the Hydro.-Growth Radiography (HGR) platform. These capsules substituted an additional thickness of plastic ablator material in place of the cryogenic layer of Deuterium- Tritium (DT) fuel. The present experiments are the first to include a DT ice layer, which enables measurements of the instability growth occurring at the fuel-ablator interface. Instability growth at the fuel-ablator interface is seeded differently in two independent NIF experiments. In the first case, a perturbation on the outside of the capsule feeds through and grows on the interface. Comparisons to an implosion without a fuel layer produce a measure of the fuel's modulation. In the second case, a modulation was directly machined on the inner ablator before the fuel layer was added. The measurement of growth in these two scenarios are compared to 2D rad-hydro modeling.