Improved gas-filled hohlraum performance on Nova with beam smoothing

Journal Article · Fri May 01 04:00:00 EDT 1998 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.872822· OSTI ID:627788

Kauffman, R L; Powers, L V; Dixit, S N; Glendinning, S G; Glenzer, S H; Kirkwood, R K; Landen, O L; MacGowan, B J; Moody, J D; Orzechowski, T J; Pennington, D M; Stone, G F; Suter, L J; Turner, R E; Weiland, T L ^[1]; Richard, A L; Blain, M A ^[2]

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1. Lawrence Livermore National Laboratory, University of California, Livermore, California94551 (United States)
2. Commissariat a lEnergie Atomique, Centre dEtudes de Limeil-Valenton, B.P. n. 27, 94190, Villeneuve-Saint-Georges (France)

Gas-filled hohlraums are presently the base line ignition target design for the National Ignition Facility. Initial Nova [E. M. Campbell {ital et al.} Rev. Sci. Instrum. {bold 57}, 2101 (1986).] experiments on gas-filled hohlraums showed that radiation temperature was reduced due to stimulated Brillouin and stimulated Raman scattering losses and that implosion symmetry had shifted compared with vacuum hohlraums and calculations. Subsequent single beam experiments imaging thermal x-ray emission showed the shift is due to laser{endash}plasma heating dynamics and filamentation in a flowing plasma. Experiments using a single beam have shown that scattering losses and effects of filamentation are reduced when the beam is spatially smoothed with a random phase plate or kinoform phase plate. Scattering is further reduced to less than 5{percent} of the incident laser energy when temporal smoothing is added.

• OSTI ID: 627788
• Report Number(s): CONF-971103--
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 5 Vol. 5; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BEAM-PLASMA SYSTEMS
INERTIAL CONFINEMENT
LASER TARGETS
LASER-PRODUCED PLASMA
LASER-RADIATION HEATING
NOVA FACILITY
PERFORMANCE
PLASMA DIAGNOSTICS