利用三维视角因子软件IRAD3D研究了神光-Ⅲ主机靶丸表面辐射驱动时变对称性和驱动强度随黑腔腔形和排布方式的变化。模拟结果表明: 采用椭球形黑腔能显著减小黑腔壁面积从而减小腔壁能量消耗并提高靶丸消耗份额; 不同腔形和排布方式下均可通过调节腔长使勒让德不对称性模P2时间积分量较小; 采用双环辐照和椭球腔形都利于缩短腔长; 四环排布利于调节P4分量, 但环向不对称性M4较差; 椭球腔双环排布能兼顾极向不对称性P2, P4和环向不对称性M4, 且靶丸表面X光驱动强度相对柱腔双环提高25%~27%。

The time dependence of irradiation drive symmetry and intensity on the capsule in different shaped hohlraums and laser arrangement is investigated by a 3D view-factor code called IRAD3D. The simulation results show that the loss of energy by the wall of hohlraum is reduced for a much smaller hohlraum area in the ellipsoidal-shaped hohlraum, resulting in an increase in the fraction of energy absorbed by the capsule. The time-integrated Legendre mode P2 of asymmetry can be controlled in a low level in a validated length of hohlraum. The hohlraum can be shorter in ellipsoidal-hohlraum with two-cones irradiation. A smaller Legendre mode P4 is attained in a four-cones irradiation system but a worse mode M4 of azimuthal asymmetry appears. All of the asymmetry modes are in a good level in the ellipsoidal-hohlraum with two-cones irradiation, meanwhile there is a 25%-27% increase in the irradiation drive flux onto the capsule compared with the cylindrical hohlraums.