Two-dimensional simulations of plastic-shell, direct-drive implosions on OMEGA

Journal Article · Tue Mar 01 00:00:00 EST 2005 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.1857530· OSTI ID:20698381

Radha, P B; Goncharov, V N; Collins, T J.B.; Delettrez, J A; Elbaz, Y; Glebov, V Yu; Keck, R L; Keller, D E; Knauer, J P; Marozas, J A; Marshall, F J; McKenty, P W; Meyerhofer, D D; Regan, S P; Sangster, T C; Shvarts, D; Skupsky, S; Srebro, Y; Town, R P.J.; Stoeckl, C ^[1]

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1. Laboratory for Laser Energetics, University of Rochester, 250 E. River Road, Rochester, New York 14623 (United States)

Multidimensional hydrodynamic properties of high-adiabat direct-drive plastic-shell implosions on the OMEGA laser system [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] are investigated using the multidimensional hydrodynamic code, DRACO [D. Keller et al., Bull. Am. Phys. Soc. 44, 37 (1999)]. Multimode simulations including the effects of nonuniform illumination and target roughness indicate that shell stability during the acceleration phase plays a critical role in determining target performance. For thick shells that remain integral during the acceleration phase, target yields are significantly reduced by the combination of the long-wavelength (l<10) modes due to surface roughness and beam imbalance and the intermediate modes (20{<=}l{<=}50) due to single-beam nonuniformities. The neutron-production rate for these thick shells truncates relative to one-dimensional (1D) predictions. The yield degradation in the thin shells is mainly due to shell breakup at short wavelengths ({lambda}{approx}{delta}, where {delta} is the in-flight shell thickness). The neutron-rate curves for the thinner shells have significantly lower amplitudes and a fall-off that is less steep than 1D rates. DRACO simulation results are consistent with experimental observations.

• OSTI ID: 20698381
• Journal Information: Physics of Plasmas, Vol. 12, Issue 3; Other Information: DOI: 10.1063/1.1857530; (c) 2005 American Institute of Physics; 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
ABLATION
LASER IMPLOSIONS
LASER-RADIATION HEATING
LASERS
PLASMA SIMULATION
ROUGHNESS
TWO-DIMENSIONAL CALCULATIONS