Suppression of the Rayleigh-Taylor instability due to self-radiation in a multiablation target.

A scheme to suppress the Rayleigh-Taylor instability has been investigated for a direct-drive inertial fusion target. In a high-Z doped-plastic target, two ablation surfaces are formed separately-one driven by thermal radiation and the other driven by electron conduction. The growth of the Rayleigh-Taylor instability is significantly suppressed on the radiation-driven ablation surface inside the target due to the large ablation velocity and long density scale length. A significant reduction of the growth rate was observed in simulations and experiments using a brominated plastic target. A new direct-drive pellet was designed using this scheme.

[1]  Hiroshi Azechi,et al.  Measurements of Rayleigh-Taylor Growth Rate of Planar Targets Irradiated Directly by Partially Coherent Light , 1996 .

[2]  Denis G. Colombant,et al.  Direct-drive laser fusion: status and prospects , 1998 .

[3]  K. Nishihara.  Scaling Laws of Plasma Ablation by Thermal Radiation , 1982 .

[4]  A. Velikovich,et al.  Study of radiative plasma structures in laser driven ablating plasmas , 1999 .

[5]  J. Lindl.  Development of the indirect‐drive approach to inertial confinement fusion and the target physics basis for ignition and gain , 1995 .

[6]  K. Nishihara,et al.  Deflagration Waves in Laser Compression. I , 1978 .

[7]  V. A. Smalyuk,et al.  Single-mode, Rayleigh-Taylor growth-rate measurements on the OMEGA laser system , 2000 .

[8]  Kunioki Mima,et al.  Self‐consistent growth rate of the Rayleigh–Taylor instability in an ablatively accelerating plasma , 1985 .

[9]  Nakai,et al.  X-ray emission and transport in gold plasmas generated by 351-nm laser irradiation. , 1991, Physical review. A, Atomic, molecular, and optical physics.

[10]  G. Zimmerman,et al.  A new quotidian equation of state (QEOS) for hot dense matter , 1988 .

[11]  Denis G. Colombant,et al.  High-gain direct-drive target design for laser fusion , 2000 .

[12]  J. Nuckolls,et al.  Laser Compression of Matter to Super-High Densities: Thermonuclear (CTR) Applications , 1972, Nature.

[13]  Hiroshi Azechi,et al.  Direct-drive hydrodynamic instability experiments on the GEKKO XII laser , 1997 .

[14]  J. Dahlburg,et al.  Radiating plasma structures in ablating, laser-produced plasmas , 1995 .

[15]  Stephen E. Bodner,et al.  Rayleigh-Taylor Instability and Laser-Pellet Fusion , 1974 .

[16]  R. Town,et al.  Analysis of a direct-drive ignition capsule designed for the National Ignition Facility , 2001 .

[17]  Hiroshi Azechi,et al.  Scalings of implosion experiments for high neutron yield , 1988 .

[18]  Robert L. McCrory,et al.  Growth rates of the ablative Rayleigh–Taylor instability in inertial confinement fusion , 1998 .

[19]  Koji Tsubakimoto,et al.  Partially coherent light generated by using single and multimode optical fibers in a high‐power Nd:glass laser system , 1993 .

[20]  Samuel A. Letzring,et al.  Improved laser‐beam uniformity using the angular dispersion of frequency‐modulated light , 1989 .

[21]  A. R. Piriz,et al.  Rayleigh-Taylor instability of steady ablation fronts: The discontinuity model revisited , 1997 .

[22]  John H. Gardner,et al.  Observation of Rayleigh–Taylor growth to short wavelengths on Nike , 1999 .

[23]  John Lindl,et al.  Two-dimensional simulation of fluid instability in laser-fusion pellets , 1975 .

[24]  S. Skupsky,et al.  Improved performance of direct-drive inertial confinement fusion target designs with adiabat shaping using an intensity picket , 2003 .

[25]  H. Takabe,et al.  Radiation effects on hydrodynamic perturbation growth due to non-uniform laser irradiation , 2001 .

[26]  Sanz.  Self-consistent analytical model of the Rayleigh-Taylor instability in inertial confinement fusion. , 1994, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[27]  J. D. Kilkenny,et al.  Measurement of a Dispersion Curve for Linear-Regime Rayleigh-Taylor Growth Rates in Laser-Driven Planar Targets , 1997 .

[28]  E. Michael Campbell,et al.  The National Ignition Facility - applications for inertial fusion energy and high-energy-density science , 1999 .

[29]  H T Powell,et al.  Kinoform phase plates for focal plane irradiance profile control. , 1994, Optics letters.