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Title: Wavelength-detuning cross-beam energy transfer mitigation scheme for direct drive: Modeling and evidence from National Ignition Facility implosions

Here, cross-beam energy transfer (CBET) results from two-beam energy exchange via seeded stimulated Brillouin scattering, which detrimentally reduces laser-energy absorption for direct-drive inertial confinement fusion. Consequently, ablation pressure and implosion velocity suffer from the decreased absorption, reducing target performance in both symmetric and polar direct drive. Additionally, CBET alters the time-resolved scattered-light spectra and redistributes absorbed and scattered-light–changing shell morphology and low-mode drive symmetry. Mitigating CBET is demonstrated in inertial confinement implosions at the National Ignition Facility by detuning the laser-source wavelengths (±2.3 Å UV) of the interacting beams. In polar direct drive, wavelength detuning was shown to increase the equatorial region velocity experimentally by 16% and to alter the in-flight shell morphology. These experimental observations are consistent with design predictions of radiation–hydrodynamic simulations that indicate a 10% increase in the average ablation pressure. These results indicate that wavelength detuning successfully mitigates CBET. Simulations predict that optimized phase plates and wavelength-detuning CBET mitigation utilizing the three-legged beam layout of the OMEGA Laser System significantly increase absorption and achieve >100-Gbar hot-spot pressures in symmetric direct drive.
Authors:
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  1. Univ. of Rochester, Rochester, NY (United States). Lab. for Laser Energetics
  2. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Publication Date:
Grant/Contract Number:
NA0001944
Type:
Accepted Manuscript
Journal Name:
Physics of Plasmas
Additional Journal Information:
Journal Volume: 25; Journal Issue: 5; Journal ID: ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)
Research Org:
Univ. of Rochester, Rochester, NY (United States). Lab. for Laser Energetics
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; CBET; ICF; NIF; LPI; wavelength detuning
OSTI Identifier:
1444067
Alternate Identifier(s):
OSTI ID: 1439134

Marozas, J. A., Hohenberger, M., Rosenberg, M. J., Turnbull, D., Collins, T. J. B., Radha, P. B., McKenty, P. W., Zuegel, J. D., Marshall, F. J., Regan, S. P., Sangster, T. C., Seka, W., Campbell, E. M., Goncharov, V. N., Bowers, M. W., Di Nicola, J. -M. G., Erbert, G., MacGowan, B. J., Pelz, L. J., Moody, J., and Yang, S. T.. Wavelength-detuning cross-beam energy transfer mitigation scheme for direct drive: Modeling and evidence from National Ignition Facility implosions. United States: N. p., Web. doi:10.1063/1.5022181.
Marozas, J. A., Hohenberger, M., Rosenberg, M. J., Turnbull, D., Collins, T. J. B., Radha, P. B., McKenty, P. W., Zuegel, J. D., Marshall, F. J., Regan, S. P., Sangster, T. C., Seka, W., Campbell, E. M., Goncharov, V. N., Bowers, M. W., Di Nicola, J. -M. G., Erbert, G., MacGowan, B. J., Pelz, L. J., Moody, J., & Yang, S. T.. Wavelength-detuning cross-beam energy transfer mitigation scheme for direct drive: Modeling and evidence from National Ignition Facility implosions. United States. doi:10.1063/1.5022181.
Marozas, J. A., Hohenberger, M., Rosenberg, M. J., Turnbull, D., Collins, T. J. B., Radha, P. B., McKenty, P. W., Zuegel, J. D., Marshall, F. J., Regan, S. P., Sangster, T. C., Seka, W., Campbell, E. M., Goncharov, V. N., Bowers, M. W., Di Nicola, J. -M. G., Erbert, G., MacGowan, B. J., Pelz, L. J., Moody, J., and Yang, S. T.. 2018. "Wavelength-detuning cross-beam energy transfer mitigation scheme for direct drive: Modeling and evidence from National Ignition Facility implosions". United States. doi:10.1063/1.5022181.
@article{osti_1444067,
title = {Wavelength-detuning cross-beam energy transfer mitigation scheme for direct drive: Modeling and evidence from National Ignition Facility implosions},
author = {Marozas, J. A. and Hohenberger, M. and Rosenberg, M. J. and Turnbull, D. and Collins, T. J. B. and Radha, P. B. and McKenty, P. W. and Zuegel, J. D. and Marshall, F. J. and Regan, S. P. and Sangster, T. C. and Seka, W. and Campbell, E. M. and Goncharov, V. N. and Bowers, M. W. and Di Nicola, J. -M. G. and Erbert, G. and MacGowan, B. J. and Pelz, L. J. and Moody, J. and Yang, S. T.},
abstractNote = {Here, cross-beam energy transfer (CBET) results from two-beam energy exchange via seeded stimulated Brillouin scattering, which detrimentally reduces laser-energy absorption for direct-drive inertial confinement fusion. Consequently, ablation pressure and implosion velocity suffer from the decreased absorption, reducing target performance in both symmetric and polar direct drive. Additionally, CBET alters the time-resolved scattered-light spectra and redistributes absorbed and scattered-light–changing shell morphology and low-mode drive symmetry. Mitigating CBET is demonstrated in inertial confinement implosions at the National Ignition Facility by detuning the laser-source wavelengths (±2.3 Å UV) of the interacting beams. In polar direct drive, wavelength detuning was shown to increase the equatorial region velocity experimentally by 16% and to alter the in-flight shell morphology. These experimental observations are consistent with design predictions of radiation–hydrodynamic simulations that indicate a 10% increase in the average ablation pressure. These results indicate that wavelength detuning successfully mitigates CBET. Simulations predict that optimized phase plates and wavelength-detuning CBET mitigation utilizing the three-legged beam layout of the OMEGA Laser System significantly increase absorption and achieve >100-Gbar hot-spot pressures in symmetric direct drive.},
doi = {10.1063/1.5022181},
journal = {Physics of Plasmas},
number = 5,
volume = 25,
place = {United States},
year = {2018},
month = {5}
}

Works referenced in this record:

Polar direct drive on the National Ignition Facility
journal, May 2004
  • Skupsky, S.; Marozas, J. A.; Craxton, R. S.
  • Physics of Plasmas, Vol. 11, Issue 5, p. 2763-2770
  • DOI: 10.1063/1.1689665

Crossed-beam energy transfer in direct-drive implosions
journal, May 2012
  • Igumenshchev, I. V.; Seka, W.; Edgell, D. H.
  • Physics of Plasmas, Vol. 19, Issue 5, Article No. 056314
  • DOI: 10.1063/1.4718594