Witness foam-ball diagnostic for Nova hohlraum time-dependent drive asymmetry

Journal Article · Sun Jan 01 04:00:00 EST 1995 · Review of Scientific Instruments; (United States)

DOI:https://doi.org/10.1063/1.1146221· OSTI ID:6689700

Amendt, P; Glendinning, S G; Hammel, B A; Hay, R G; Suter, L J ^[1]

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1. Lawrence Livermore National Laboratory, University of California, P. O. Box 808, Livermore, California 94550 (United States)

Backlighting of low-density SiO[sub 2] aerogel balls (0.3 g/cc) in Nova hohlraums enables direct imaging of the indirectly driven ablative shock trajectory versus time. An immediate application of the technique is a new method for measuring drive temperature and asymmetry in Nova hohlraums. Measured drive asymmetries are exaggerated due to an increased shock speed in low-density foam balls. From the backlighter-imaged distortion of the radially converging shock, a potentially useful time-dependent flux asymmetry diagnostic is obtained. Results from a 3:1 peak-to-foot contrast ratio pulse shape ([ital ps]22) are analyzed and shown to agree with modeling. The current goal of the witness-ball effort on Nova is to identify the transition in flux on capsule from waist high (sausaging) to pole high (pancaking), thereby validating the technique as a promising symmetry diagnostic for the proposed National Ignition Facility.

• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6689700
• Journal Information: Review of Scientific Instruments; (United States), Journal Name: Review of Scientific Instruments; (United States) Vol. 66:1; ISSN 0034-6748; ISSN RSINAK
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700320* -- Plasma Diagnostic Techniques & Instrumentation-- (1992-)
700411 -- Inertial Confinement Devices-- (1992-)
ASYMMETRY
COLLOIDS
DISPERSIONS
ELECTROMAGNETIC RADIATION
FOAMS
IMAGES
IMPLOSIONS
INDIRECT DRIVE LASER IMPLOSION
IONIZING RADIATIONS
LASER IMPLOSIONS
LASER TARGETS
NOVA FACILITY
RADIATIONS
TARGETS
TIME DEPENDENCE
X RADIATION