“神光-Ⅱ”装置倍频激光直接驱动冲击波平面性的实验研究

Experimental researches on planarity of shock wave directly driven by 2ω laser beam of "Shenguang-Ⅱ" facility

设计了3套针对“神光-Ⅱ”倍频激光直接驱动的透镜阵列均匀辐照系统,并对冲击波的平面性进行了实验研究。结果表明,冲击波的平面性与透镜阵列参数、平面靶厚度、靶面位置等有关,采用列阵元数为121的透镜阵列进行激光束匀滑驱动的冲击波平面性最好,间接说明它在靶面的激光辐照是最均匀的;另外,随着靶厚的增加,冲击波平面性变差,平面区变小;而且冲击波平面性随靶面离焦位置的变化成一定的周期性变化,第2套透镜阵列焦点处的冲击波平面性最好。

Three sets of lens array （LA） uniform illumination system were designed, which were used in double-frequency laser direct drive experiments on ＂Shenguang-Ⅱ ＂ laser facility. Experimental investigations on shock planarity were carried out. The results show that the shock planarity has strong relationship with the LA＇s parameters, plane target＇s thickness and target＇s position. The shock planarity driven by the LA with 121 elements is the best, and which indirectly indicates that the illumination of the 121-element LA is the most uniform, too. Moreover, with the target thickness increasing, the shock planarity becomes worse, and the planar area becomes smaller. Also, the shock planarity showes some periodical change with the target＇s position, and the shock planarity at focal plane is the best for 121-element LA.