RAYLEIGH-TAYLOR INSTABILITY AND ITS REDUCTION IN LASER-ACCELERATED TARGETS

摘要

Rayleigh-Taylor (RT) instability is of great importance in laser fusion because its growth degrades integrity of the imploding shell and may lower the density of the imploded core plasma. The dispersion relation of RT growth rate described by the modified Bodner-Takabe formula have been intensively investigated with Gekko-XII-HIPER laser at ILE, Osaka University. The growth rate is strongly dependent on the density structure of the accelerated target, and hence, there is a possibility to reduce RT growth by controlling the energy transport in the laser-driven target. We recently demonstrated two types of technique to reduce RT growth: one is double ablation in which radiation transport is utilized, and the other is two-color laser irradiation in which induced nonlocal electron transport is enhanced. Both of them will be effective in reducing the RT instability growth in inertial fusion targets.