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%。

Numerical simulation of effect of laser nonuniformity on interior interface

Using the LARED-S code and referring to the NIF direct-drive DT ignition target,the effect of laser nonuniformity on the interior interface in direct-drive spherical implosion with high convergence ratio was numerically studied.The two-dimensional results show that the implosion with high convergence ratio is sensitive to the nonuniformity of driving laser,and the growth of hydrodynamic instability on interior interface destroys the symmetric-drive and reduces the volume of central hot spot observably.Taking the limit that perturbation amplitude is equal to 1/3 radius of central hot spot,the simulation also gives that the requirements for the laser uniformity for different mode number(less than 12) on simple physical model are between 2.5%~0.25%,and the modes between 8~10 have the most rigorous requirement which is about 0.25%.