Symmetry experiments in gas-filled hohlraums at NOVA

Journal Article · Wed May 01 00:00:00 EDT 1996 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.871999· OSTI ID:283727

Delamater, N D; Murphy, T J; Hauer, A A ^[1]; Kauffman, R L ^[2]; Richard, A L ^[3]; Lindman, E L; Magelssen, G R; Wilde, B H; Harris, D B ^[1]; Failor, B A ^[4]; Wallace, J ^[1]; Powers, L V; Pollaine, S M; Suter, L J ^[2]; Chrien, R ^[1]; Shepard, T D ^[2]; Rose, H A ^[1]; Williams, E A; Nelson, M B; Cable, M D ^[2] ; Moore, J B; Salazar, M A ^[1]; Gifford, K ^[5]

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1. Los Alamos National Laboratory, MS E-526, Los Alamos, New Mexico 87545 (United States)
2. Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)
3. Centre DEtudes De Limeil-Valenton (France)
4. Physics International, San Leandro, California 94577 (United States)
5. General Atomics, San Diego, California 85608 (United States)

Understanding drive symmetry in gas-filled hohlraums is currently of interest because the baseline design of the indirect drive ignition target for the planned National Ignition Facility uses a gas-filled hohlraum. This paper reports on the results of a series of experiments performed at the Nova laser [C. Bibeau {ital et} {ital al}. Appl. Opt. {bold 31}, 5799 (1992)] facility at Lawrence Livermore National Laboratory with the goal of understanding time-dependent drive symmetry in gas filled hohlraums. Time-dependent symmetry data from capsule implosions and reemission targets in gas-filled hohlraums are discussed. Results of symmetry measurements using thin wall gas-filled hohlraums are also discussed. The results show that the gas is effective in impeding the motion of the wall blowoff material, and that the resulting implosion performance of the capsule is not significantly degraded from vacuum results. The implosion symmetry in gas differs from vacuum results with similar laser pointing indicating a shift in beam position on the hohlraum wall and hotter drive at the capsule{close_quote}s poles than at the equator. A theory has been proposed to explain the observed shift as a plasma physics effect: beam steering due to filamentation and transverse plasma flows. {copyright} {ital 1996 American Institute of Physics.}

• Research Organization: Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 283727
• Journal Information: Physics of Plasmas, Vol. 3, Issue 5; Other Information: PBD: May 1996
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION
INDIRECT DRIVE LASER IMPLOSION
SYMMETRY
NOVA FACILITY
LASER FUSION REACTORS
LASER RADIATION
ICF DEVICES
ABLATION
LASER-PRODUCED PLASMA
BEAM-PLASMA SYSTEMS
GOLD
X RADIATION