Two-dimensional simulations of the neutron yield in cryogenic deuterium-tritium implosions on OMEGA

Journal Article · Fri Oct 15 00:00:00 EDT 2010 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3491467· OSTI ID:21421272

Hu, S X; Goncharov, V N; Radha, P B; Marozas, J A; Skupsky, S; Boehly, T R; Sangster, T C; Meyerhofer, D D; McCrory, R L ^[1]

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

Maximizing the neutron yield to obtain energy gain is the ultimate goal for inertial confinement fusion. Nonuniformities seeded by target and laser perturbations can disrupt neutron production via the Rayleigh-Taylor instability growth. To understand the effects of perturbations on the neutron yield of cryogenic DT implosions on the Omega Laser Facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)], two-dimensional DRACO[P. B. Radha et al., Phys. Plasmas 12, 056307 (2005)] simulations have been performed to systematically investigate each perturbation source and their combined effects on the neutron-yield performance. Two sources of nonuniformity accounted for the neutron-yield reduction in DRACO simulations: target offset from the target chamber center and laser imprinting. The integrated simulations for individual shots reproduce the experimental yield-over-clean (YOC) ratio within a factor of 2 or better. The simulated neutron-averaged ion temperatures <T{sub i}> is only about 10%-15% higher than measurements. By defining the temperature-over-clean, its relationship to YOC provides an indication of how much the hot-spot volume and density are perturbed with respect to the uniform situation. Typically, the YOC in OMEGA experiments is of the order of {approx}5%. The simulation results suggest that YOC can be increased to the ignition hydroequivalent level of 15%-20% (with <{rho}R>=200-300 mg/cm{sup 2}) by maintaining a target offset of less than 10 {mu}m and employing beam smoothing by spectral dispersion.

• OSTI ID: 21421272
• Journal Information: Physics of Plasmas, Vol. 17, Issue 10; Other Information: DOI: 10.1063/1.3491467; (c) 2010 American Institute of Physics; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
DEUTERIUM
DISTURBANCES
IMPLOSIONS
INERTIAL CONFINEMENT
ION TEMPERATURE
LASER-PRODUCED PLASMA
LASERS
NEUTRONS
NUCLEAR REACTION YIELD
PLASMA DENSITY
RAYLEIGH-TAYLOR INSTABILITY
SIMULATION
TARGET CHAMBERS
TRITIUM
TWO-DIMENSIONAL CALCULATIONS
ACCELERATOR FACILITIES
BARYONS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CONFINEMENT
ELEMENTARY PARTICLES
FERMIONS
HADRONS
HYDROGEN ISOTOPES
INSTABILITY
ISOTOPES
LIGHT NUCLEI
NUCLEI
NUCLEONS
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
PLASMA
PLASMA CONFINEMENT
RADIOISOTOPES
STABLE ISOTOPES
YEARS LIVING RADIOISOTOPES
YIELDS