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Title: Hydrodynamic instability growth and mix experiments at the National Ignition Facility

Journal Article · · Physics of Plasmas
DOI:https://doi.org/10.1063/1.4872026· OSTI ID:1229809

Hydrodynamic instability growth and its effects on implosion performance were studied at the National Ignition Facility. Implosion performance and mix have been measured at peak compression using plastic shells filled with tritium gas and containing embedded localized carbon-deuterium diagnostic layers in various locations in the ablator. Neutron yield and ion temperature of the deuterium-tritium fusion reactions were used as a measure of shell-gas mix, while neutron yield of the tritium-tritium fusion reaction was used as a measure of implosion performance. The results have indicated that the low-mode hydrodynamic instabilities due to surface roughness were the primary culprits for yield degradation, with atomic ablator-gas mix playing a secondary role. Additionally, spherical shells with pre-imposed 2D modulations were used to measure instability growth in the acceleration phase of the implosions. The capsules were imploded using ignition-relevant laser pulses, and ablation-front modulation growth was measured using x-ray radiography for a shell convergence ratio of ~2. The measured growth was in good agreement with that predicted, thus validating simulations for the fastest growing modulations with mode numbers up to 90 in the acceleration phase. Future experiments will be focused on measurements at higher convergence, higher-mode number modulations, and growth occurring during the deceleration phase.

Research Organization:
Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
Sponsoring Organization:
USDOE
Grant/Contract Number:
AC52-07NA27344; NA0001857
OSTI ID:
1229809
Report Number(s):
LLNL-JRNL-647156
Journal Information:
Physics of Plasmas, Vol. 21, Issue 5; ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 59 works
Citation information provided by
Web of Science

References (55)

Multimode Rayleigh-Taylor Experiments on Nova journal July 1994
Progress towards ignition on the National Ignition Facility journal July 2013
Extracting core shape from x-ray images at the National Ignition Facility journal October 2012
Evolution of Shell Nonuniformities near Peak Compression of a Spherical Implosion journal September 2001
Deceleration phase of inertial confinement fusion implosions journal May 2002
Observation of Rayleigh–Taylor growth to short wavelengths on Nike journal February 1999
Optical and plasma smoothing of laser imprinting in targets driven by lasers with SSD bandwidths up to 1 THz journal May 2001
Onset of Hydrodynamic Mix in High-Velocity, Highly Compressed Inertial Confinement Fusion Implosions journal August 2013
The ablation-front Rayleigh–Taylor dispersion curve in indirect drive journal May 2001
Detailed implosion modeling of deuterium-tritium layered experiments on the National Ignition Facility journal May 2013
Single-mode, Rayleigh-Taylor growth-rate measurements on the OMEGA laser system journal January 2000
Three-dimensional simulations of the implosion of inertial confinement fusion targets journal September 1991
Precision Shock Tuning on the National Ignition Facility journal May 2012
Rayleigh-Taylor Growth Measurements in the Acceleration Phase of Spherical Implosions on OMEGA journal September 2009
Ablative Stabilization of the Deceleration Phase Rayleigh-Taylor Instability journal November 2000
Ignition scaling laws and their application to capsule design journal May 2001
Rayleigh–Taylor instability in the deceleration phase of spherical implosion experiments journal June 2002
Numerical Modeling of the Sensitivity of X-Ray Driven Implosions to Low-Mode Flux Asymmetries journal February 2013
Measurements of Rayleigh-Taylor Growth Rate of Planar Targets Irradiated Directly by Partially Coherent Light journal January 1997
Measurement and Simulation of Laser Imprinting and Consequent Rayleigh-Taylor Growth journal March 1996
Diagnosing implosion performance at the National Ignition Facility (NIF) by means of neutron spectrometry journal March 2013
Rayleigh-Taylor instability growth rates in targets accelerated with a laser beam smoothed by induced spatial incoherence journal June 1987
Implosion dynamics measurements at the National Ignition Facility journal December 2012
K-L turbulence model for the self-similar growth of the Rayleigh-Taylor and Richtmyer-Meshkov instabilities journal August 2006
Three‐dimensional simulations of Nova high growth factor capsule implosion experiments journal May 1996
Nonlinear Rayleigh-Taylor Evolution of a Three-Dimensional Multimode Perturbation journal May 1998
Direct-drive hydrodynamic instability experiments on the GEKKO XII laser journal November 1997
NIF Ignition Campaign Target Performance and Requirements: Status May 2012 journal April 2013
Reduced ablative Rayleigh–Taylor growth measurements in indirectly driven laminated foils journal January 2011
Hot-Spot Mix in Ignition-Scale Inertial Confinement Fusion Targets journal July 2013
Rayleigh-Taylor growth measurements of three-dimensional modulations in a nonlinear regime journal May 2006
Indirect drive ablative Rayleigh–Taylor experiments with rugby hohlraums on OMEGA journal September 2009
A study of ALE simulations of Rayleigh–Taylor instability journal March 2001
The Physics of Inertial Fusion book January 2004
On the stability of the spherical shape of a vapor cavity in a liquid journal January 1956
Cryogenic thermonuclear fuel implosions on the National Ignition Facility journal May 2012
Performance of High-Convergence, Layered DT Implosions with Extended-Duration Pulses at the National Ignition Facility journal November 2013
Fourier-Space Nonlinear Rayleigh-Taylor Growth Measurements of 3D Laser-Imprinted Modulations in Planar Targets journal November 2005
Measurement of the T + T Neutron Spectrum Using the National Ignition Facility journal August 2013
Laser Compression of Matter to Super-High Densities: Thermonuclear (CTR) Applications journal September 1972
Progress in the indirect-drive National Ignition Campaign journal November 2012
The National Ignition Facility journal December 2004
Diagnosing and controlling mix in National Ignition Facility implosion experiments journal May 2011
Three-dimensional Rayleigh-Taylor instability of spherical systems journal July 1990
Saturation of the Rayleigh-Taylor Growth of Broad-Bandwidth Laser-Imposed Nonuniformities in Planar Targets journal December 1998
Stabilizing Effect of Anisotropic Thermal Diffusion on the Ablative Rayleigh-Taylor Instability journal June 2007
Observation of Self-Similar Behavior of the 3D, Nonlinear Rayleigh-Taylor Instability journal December 2005
Measurements of direct drive laser imprint in thin foils by radiography using an x-ray laser backlighter journal May 1997
The instability of liquid surfaces when accelerated in a direction perpendicular to their planes. I journal March 1950
Experimental Comparison of Classical versus Ablative Rayleigh-Taylor Instability journal June 1996
Measurements of an Ablator-Gas Atomic Mix in Indirectly Driven Implosions at the National Ignition Facility journal January 2014
Taylor instability in shock acceleration of compressible fluids journal May 1960
Measurement of a Dispersion Curve for Linear-Regime Rayleigh-Taylor Growth Rates in Laser-Driven Planar Targets journal April 1997
The National Ignition Facility: Ushering in a new age for high energy density science journal April 2009
Shock timing experiments on the National Ignition Facility: Initial results and comparison with simulation journal April 2012