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M. Nakai, H. Azechi, M. Honda, R. Kodama,
N. Miyanaga, T. Nagaya, S. Nakai, M. Nakatsuka,
K. Nishihara, H. Nishimura, T. Norimatsu,
K. Shigemori, H. Shiraga, H. Takabe, T. Yamanaka,
K. Mima
Institute of Laser Engineering, Osaka University, Suita, Osaka
Institute for Laser Technology, Utsubo-honmachi Nishiku Osaka
Osaka Institute of Technology, Omiya, Asahi-ku, Osaka
Abstract. A series of elementary experiments on the hydrodynamic instability
in the inertial confinement fusion have been conducted at the GEKKO XII
laser system. Perturbation growth of the target areal density due to the
rippled shock wave driven from the perturbed surface and/or by nonuniform
laser illumination has been extensively investigated to show an analytic
model of imprint well predicts the experimental results under the condition
that (perturbation wavenumber) x (thickness of the shock compressed region)
< 1. Deformation of the laser illumination surface fed by the perturbation
on the rear surface was examined using a planar target with flat (front) and
corrugated (rear) surfaces. The displacement of the ablation front is
quantitatively explained by the perturbation on the arrival time of the
rippled rarefaction wave and that on the subsequent acceleration. Linear
growth rate of the Rayleigh-Taylor instability has been measured for the
various conditions to confirm the effect of the nonlocal electron heat
conduction.
IAEA 2001
