Recent progress in laser fusion research at Osaka University: Uniformity and stability issues

Journal Article · Sun May 01 04:00:00 EDT 1994 · Physics of Plasmas; (United States)

DOI:https://doi.org/10.1063/1.870667· OSTI ID:6691688

Nishihara, K; Murakami, M; Azechi, H; Jitsuno, T; Kanabe, T; Katayama, M; Miyanaga, N; Nakai, M; Nakatsuka, M; Tsubakimoto, K; Nakai, S ^[1]

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1. Institute of Laser Engineering, Osaka University, Osaka 565 (Japan)

Improvement of laser irradiation uniformity in the Gekko XII system [IEEE J. Quantum Electron. [bold QE]-[bold 17], 1639 (1981)], both single beam pattern and power balance, is discussed. Substantial reduction of laser absorption nonuniformity is obtained for spherical harmonic modes greater than 15 by introducing spectrally dispersed amplified spontaneous emission. No perturbation growth is observed in flat foils accelerated by spectrally dispersed amplified spontaneous emission. Dependences of laser absorption uniformity on beam pattern and power imbalance are investigated in detail. The design goal of the power imbalance in the precision Gekko XII system is 3% in peak to valley, and laser absorption nonuniformity is estimated to be a few percent. Growth of hydrodynamic instabilities is analyzed for high convergence ratio implosions in the precision Gekko XII system.

• OSTI ID: 6691688
• Journal Information: Physics of Plasmas; (United States), Journal Name: Physics of Plasmas; (United States) Vol. 1:5; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700350* -- Plasma Production
Heating
Current Drive
& Interactions-- (1992-)
ABLATION
ABSORPTION
CONFINEMENT
DESIGN
ELECTROMAGNETIC RADIATION
FUNCTIONS
IMPLOSIONS
INERTIAL CONFINEMENT
INSTABILITY
INSTABILITY GROWTH RATES
IRRADIATION
LASER IMPLOSIONS
LASER RADIATION
LASER-PRODUCED PLASMA
LEGENDRE POLYNOMIALS
PLASMA
PLASMA CONFINEMENT
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
POLYNOMIALS
RADIATIONS
SORPTION