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Title: Short-wavelength and three-dimensional instability evolution in National Ignition Facility ignition capsule designs

Abstract

Ignition capsule designs for the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 443, 2841 (2004)] have continued to evolve in light of improved physical data inputs, improving simulation techniques, and, most recently, experimental data from a growing number of NIF sub-ignition experiments. This paper summarizes a number of recent changes to the cryogenic capsule design and some of our latest techniques in simulating its performance. Specifically, recent experimental results indicated harder x-ray drive spectra in NIF hohlraums than were predicted and used in previous capsule optimization studies. To accommodate this harder drive spectrum, a series of high-resolution 2-D simulations, resolving Legendre mode numbers as high as 2000, were run and the germanium dopant concentration and ablator shell thicknesses re-optimized accordingly. Simultaneously, the possibility of cooperative or nonlinear interaction between neighboring ablator surface defects has motivated a series of fully 3-D simulations run with the massively parallel HYDRA code. These last simulations include perturbations seeded on all capsule interfaces and can use actual measured shell surfaces as initial conditions. 3-D simulations resolving Legendre modes up to 200 on large capsule sectors have run through ignition and burn, and higher resolution simulations resolvingmore » as high as mode 1200 have been run to benchmark high-resolution 2-D runs. Finally, highly resolved 3-D simulations have also been run of the jet-type perturbation caused by the fill tube fitted to the capsule. These 3-D simulations compare well with the more typical 2-D simulations used in assessing the fill tube's impact on ignition. Coupled with the latest experimental inputs from NIF, our improving simulation capability yields a fuller and more accurate picture of NIF ignition capsule performance.« less

Authors:
; ; ; ; ; ;  [1]
  1. Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)
Publication Date:
OSTI Identifier:
22043406
Resource Type:
Journal Article
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 18; Journal Issue: 8; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1070-664X
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; BENCHMARKS; COMPARATIVE EVALUATIONS; DESIGN; FUELS; HARD X RADIATION; INTERACTIONS; INTERFACES; PERTURBATION THEORY; PLASMA; PLASMA INSTABILITY; PLASMA JETS; PLASMA SIMULATION; SPECTRA; SURFACES; THERMONUCLEAR IGNITION; THERMONUCLEAR REACTORS; THREE-DIMENSIONAL CALCULATIONS; US NATIONAL IGNITION FACILITY; WAVELENGTHS; X-RAY SOURCES

Citation Formats

Clark, D S, Haan, S W, Cook, A W, Edwards, M J, Hammel, B A, Koning, J M, and Marinak, M M. Short-wavelength and three-dimensional instability evolution in National Ignition Facility ignition capsule designs. United States: N. p., 2011. Web. doi:10.1063/1.3609834.
Clark, D S, Haan, S W, Cook, A W, Edwards, M J, Hammel, B A, Koning, J M, & Marinak, M M. Short-wavelength and three-dimensional instability evolution in National Ignition Facility ignition capsule designs. United States. https://doi.org/10.1063/1.3609834
Clark, D S, Haan, S W, Cook, A W, Edwards, M J, Hammel, B A, Koning, J M, and Marinak, M M. 2011. "Short-wavelength and three-dimensional instability evolution in National Ignition Facility ignition capsule designs". United States. https://doi.org/10.1063/1.3609834.
@article{osti_22043406,
title = {Short-wavelength and three-dimensional instability evolution in National Ignition Facility ignition capsule designs},
author = {Clark, D S and Haan, S W and Cook, A W and Edwards, M J and Hammel, B A and Koning, J M and Marinak, M M},
abstractNote = {Ignition capsule designs for the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 443, 2841 (2004)] have continued to evolve in light of improved physical data inputs, improving simulation techniques, and, most recently, experimental data from a growing number of NIF sub-ignition experiments. This paper summarizes a number of recent changes to the cryogenic capsule design and some of our latest techniques in simulating its performance. Specifically, recent experimental results indicated harder x-ray drive spectra in NIF hohlraums than were predicted and used in previous capsule optimization studies. To accommodate this harder drive spectrum, a series of high-resolution 2-D simulations, resolving Legendre mode numbers as high as 2000, were run and the germanium dopant concentration and ablator shell thicknesses re-optimized accordingly. Simultaneously, the possibility of cooperative or nonlinear interaction between neighboring ablator surface defects has motivated a series of fully 3-D simulations run with the massively parallel HYDRA code. These last simulations include perturbations seeded on all capsule interfaces and can use actual measured shell surfaces as initial conditions. 3-D simulations resolving Legendre modes up to 200 on large capsule sectors have run through ignition and burn, and higher resolution simulations resolving as high as mode 1200 have been run to benchmark high-resolution 2-D runs. Finally, highly resolved 3-D simulations have also been run of the jet-type perturbation caused by the fill tube fitted to the capsule. These 3-D simulations compare well with the more typical 2-D simulations used in assessing the fill tube's impact on ignition. Coupled with the latest experimental inputs from NIF, our improving simulation capability yields a fuller and more accurate picture of NIF ignition capsule performance.},
doi = {10.1063/1.3609834},
url = {https://www.osti.gov/biblio/22043406}, journal = {Physics of Plasmas},
issn = {1070-664X},
number = 8,
volume = 18,
place = {United States},
year = {Mon Aug 15 00:00:00 EDT 2011},
month = {Mon Aug 15 00:00:00 EDT 2011}
}