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Title: Measurement of ablative Richtmyer-Meshkov evolution from laser imprint

Authors:
ORCiD logo [1];  [1];  [2];  [3]; ORCiD logo [3]; ORCiD logo [1];  [1]; ORCiD logo [1];  [4]
  1. Lawrence Livermore National Laboratory, Livermore, California 94550, USA
  2. Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
  3. CEA, DAM, DIF, F-91297 Arpajon, France, University Bordeaux-CNRS-CEA, CELIA, UMR 5107, 33405 Talence, France
  4. CEA-CESTA, 15 avenue des Sablières, CS 60001, 33116 Le Barp Cedex, France
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1394008
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 24; Journal Issue: 10; Related Information: CHORUS Timestamp: 2018-02-14 13:14:32; Journal ID: ISSN 1070-664X
Publisher:
American Institute of Physics
Country of Publication:
United States
Language:
English

Citation Formats

Martinez, D. A., Smalyuk, V. A., Igumenshchev, I. V., Delorme, B., Casner, A., Masse, L., Park, H. -S., Remington, B. A., and Olazabal-Loumé, M. Measurement of ablative Richtmyer-Meshkov evolution from laser imprint. United States: N. p., 2017. Web. doi:10.1063/1.4991703.
Martinez, D. A., Smalyuk, V. A., Igumenshchev, I. V., Delorme, B., Casner, A., Masse, L., Park, H. -S., Remington, B. A., & Olazabal-Loumé, M. Measurement of ablative Richtmyer-Meshkov evolution from laser imprint. United States. doi:10.1063/1.4991703.
Martinez, D. A., Smalyuk, V. A., Igumenshchev, I. V., Delorme, B., Casner, A., Masse, L., Park, H. -S., Remington, B. A., and Olazabal-Loumé, M. 2017. "Measurement of ablative Richtmyer-Meshkov evolution from laser imprint". United States. doi:10.1063/1.4991703.
@article{osti_1394008,
title = {Measurement of ablative Richtmyer-Meshkov evolution from laser imprint},
author = {Martinez, D. A. and Smalyuk, V. A. and Igumenshchev, I. V. and Delorme, B. and Casner, A. and Masse, L. and Park, H. -S. and Remington, B. A. and Olazabal-Loumé, M.},
abstractNote = {},
doi = {10.1063/1.4991703},
journal = {Physics of Plasmas},
number = 10,
volume = 24,
place = {United States},
year = 2017,
month =
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on September 22, 2018
Publisher's Accepted Manuscript

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  • A mode-coupling model is developed to treat the multimode evolution of the ablative Richtmyer-Meshkov (RM) and Landau-Darrieus (LD) instability in the laser imprint of planar targets. Using this mode coupling model, the multimode power spectrum of the RM and LD instability is computed. For the RM instability, mode-coupling effects lead to a broadening of the oscillatory minima found in linear RM theory. For the LD instability, mode-coupling effects generate an inverse power law spectrum.
  • The Richtmyer-Meshkov instability (RMI) at the ablation front of laser-irradiated planar targets is investigated by two-dimensional numerical hydrodynamics simulations. The linear evolution of perturbations seeded either by surface roughness or target inhomogeneity is studied for perturbation wavelengths in the range 10{<=}{lambda}{<=}400 {mu}m and laser intensity 4x10{sup 12{<=}}I{<=}4x10{sup 14} W/cm{sup 2} (with laser wavelength {lambda}{sub laser}=0.35 {mu}m). Thin and thick cryogenic deuterium or deuterium-tritium (DT) planar targets are considered. For targets irradiated at constant intensity, it is found that perturbations with wavelength below a given threshold perform damped oscillations, while perturbations above such a threshold are unstable and oscillate with growingmore » amplitude. This is qualitatively in agreement with theoretical predictions by Goncharov et al. [Phys. Plasmas 13, 012702 (2006)], according to which ablation related processes stabilize perturbations with kD{sub c}>>1, where D{sub c} is the distance between the ablation front and critical density for laser propagation. For kD{sub c}<1 a weakly growing Landau-Darrieus instability (LDI) is instead excited. The stability threshold increases substantially with laser intensity, given the dependence of D{sub c} on laser intensity I (roughly D{sub c{proportional_to}}I, according to the present simulations). Direct-drive laser fusion targets are irradiated by time-shaped pulses, with a low intensity initial foot. In this case, perturbations with wavelengths below some threshold (about 10 {mu}m, for typical ignition-class all-DT targets) are damped after an initial growth. In a thin target, initial perturbations, either damped or amplified by RMI and LDI, seed the subsequent Rayleigh-Taylor instability. Finally, it is shown that RMI growth of fusion targets can be reduced by using laser pulses including an initial adiabat-shaping picket (originally proposed to reduce the growth of Rayleigh-Taylor instability).« less
  • The temporal development of laser driven single mode perturbations in thin Al foils has been measured using extreme ultraviolet (XUV) laser radiography. 15, 30, 70 and 90 {mu}m single modes were imprinted on 2 {mu}m thick Al foils with an optical driver laser at 527 nm for intensities in the range 5{times}10{sup 12} to 1.5{times}10{sup 13}Wcm{sup {minus}2}. The magnitude of the imprinted perturbation at the time of shock break out was determined by fitting to the data estimated curves of growth of the Rayleigh{endash}Taylor instability after shock break out. The efficiency of imprinting is independent of perturbation wavelength in themore » parameter range of this experiment, suggesting little influence of thermal conduction smoothing. The results are of interest for directly driven inertially confined fusion. {copyright} {ital 1998 American Institute of Physics.}« less
  • The first observations of the interaction of the Richtmyer-Meshkov (RM) instability with reflected shock and rarefaction waves in laser-driven targets are reported. The RM growth is started by a shock wave incident upon a rippled interface between low-density foam and solid plastic. The subsequent interaction of secondary rarefaction and/or shock waves arriving from the ablation front and the rear surface of the target with the RM-unstable interface stops the perturbation growth and reverses its direction. The ensuing exponential Rayleigh-Taylor growth thus can sometimes proceed with an inverted phase.
  • Theory of the ablative Richtmyer-Meshkov instability is presented. It is shown that the main stabilizing mechanism of the ablation-front perturbations during the shock transit time is the dynamic overpressure that causes perturbation oscillations. The amplitude of the oscillation is proportional to c{sub s}/{radical}(V{sub a}V{sub bl}) and its frequency is {omega}=k{radical}(V{sub a}V{sub bl}) , where k is the wave number, and c{sub s} , V{sub a} , and V{sub bl} are sound speed, ablation, and blow-off plasma velocities, respectively. {copyright} {ital 1999} {ital The American Physical Society}