Optical smoothing of laser imprinting in planar-target experiments on OMEGA EP using multi-FM 1-D smoothing by spectral dispersion

Journal Article · Thu Sep 15 00:00:00 EDT 2016 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4962185· OSTI ID:22599867

Shvydky, A.; Marozas, J. A.; Bonino, M. J.; Canning, D.; Collins, T. J. B.; Dorrer, C.; Kessler, T. J.; Kruschwitz, B. E.; McKenty, P. W.; Regan, S. P.; Sangster, T. C.; Zuegel, J. D. ^[1]; Fiksel, G. ^[2]; Meyerhofer, D. D. ^[3]

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1. Laboratory for Laser Energetics, University of Rochester, 250 East River Road Rochester, Rochester, New York 14623 (United States)
2. Nuclear Engineering and Radiological Sciences (NERS), University of Michigan, Ann Arbor, Michigan 48109 (United States)
3. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

Direct-drive ignition on the National Ignition Facility (NIF) requires single-beam smoothing to minimize imprinting of laser nonuniformities that can negatively affect implosion performance. One-dimensional, multi-FM smoothing by spectral dispersion (SSD) has been proposed to provide the required smoothing [Marozas et al., Bull. Am. Phys. Soc. 55, 294 (2010)]. A prototype multi-FM SSD system has been integrated into the NIF-like beamline of the OMEGA EP Laser System. Experiments have been performed to verify the smoothing performance by measuring Rayleigh–Taylor growth rates in planar targets of laser-imprinted and preimposed surface modulations. Multi-FM 1-D SSD has been observed to reduce imprint levels by ∼50% compared to the nominal OMEGA EP SSD system. The experimental results are in agreement with 2-D DRACO simulations using realistic, time-dependent far-field spot-intensity calculations that emulate the effect of SSD.

• OSTI ID: 22599867
• Journal Information: Physics of Plasmas, Vol. 23, Issue 9; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BEAMS
COMPARATIVE EVALUATIONS
COMPUTERIZED SIMULATION
DISPERSIONS
IMPLOSIONS
LASERS
MODULATION
ONE-DIMENSIONAL CALCULATIONS
PERFORMANCE
THERMONUCLEAR IGNITION
TIME DEPENDENCE
TWO-DIMENSIONAL CALCULATIONS
US NATIONAL IGNITION FACILITY