Tent-induced perturbations on areal density of implosions at the National Ignition Facility

Journal Article · Fri May 15 00:00:00 EDT 2015 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4921218· OSTI ID:22410411

Field, J. E.; Hammel, B. A.; Landen, O. L.; Haan, S. W.; Aracne-Ruddle, C.; Benedetti, L. R.; Bradley, D. K.; Callahan, D. A.; Dewald, E. L.; Doeppner, T.; Edwards, M. J.; Hurricane, O. A.; Izumi, N.; Jones, O. A.; Ma, T.; Meezan, N. B.; Nagel, S. R.; Rygg, J. R.; Stadermann, M. ^[1]; others, and

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1. Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

Areal density non-uniformities seeded by time-dependent drive variations and target imperfections in Inertial Confinement Fusion (ICF) targets can grow in time as the capsule implodes, with growth rates that are amplified by instabilities. Here, we report on the first measurements of the perturbations on the density and areal density profiles induced by the membranes used to hold the capsule within the hohlraum in indirect drive ICF targets. The measurements are based on the reconstruction of the ablator density profiles from 2D radiographs obtained using pinhole imaging coupled to area backlighting, as close as 150 ps to peak compression. Our study shows a clear correlation between the modulations imposed on the areal density and measured neutron yield, and a 3× reduction in the areal density perturbations comparing a high-adiabat vs. low-adiabat pulse shape.

• OSTI ID: 22410411
• Journal Information: Physics of Plasmas, Vol. 22, Issue 5; Other Information: (c) 2015 AIP Publishing LLC; 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
CAPSULES
COMPRESSION
DENSITY
DISTURBANCES
IMPLOSIONS
INDIRECT DRIVE ICF
INERTIAL CONFINEMENT
NEUTRONS
PLASMA INSTABILITY
PULSE SHAPERS
TIME DEPENDENCE
US NATIONAL IGNITION FACILITY