激光非均匀性对内界面变形影响的数值模拟

 使用LARED-S程序,参照NIF直接驱动DT点火靶,模拟研究了激光非均匀性对高收缩比球内爆内界面变形的影响。2维数值模拟计算表明：直接驱动高收缩比内爆对驱动激光非均匀性非常敏感,内界面流体不稳定性的发展严重破坏靶丸的对称压缩,使中心热斑的体积显著减小。以最大压缩时扰动增长幅度不超过热斑半径的1/3为限,模拟给出不同模数的低阶扰动模(模数小于等于12)对驱动激光均匀性的要求在2.5%～0.25%之间,其中模数在8～10之间的扰动模对激光功率均匀性的要求最严格,约为0.25%。     

Interface Width Effect on the Weakly Nonlinear Rayleigh–Taylor Instability in Spherical Geometry

Interface width effect on the spherical Rayleigh–Taylor instability in the weakly nonlinear regime is studied by numerical simulations.For Legendre perturbation mode P_n with wave number K_n and interface half-width L,the commonly adopted empirical linear growth rate formula γ_n^em(L)=γn/√1 + K_nL is found to be sufficient in spherical geometry.At the weakly nonlinear stage,the interface width affects the mode coupling processes.The development o...