氘氘-塑料靶丸变收缩比内爆物理实验研究

Variations of implosion performance with compression ratio in plastic DD filled capsule implosion experiment

在神光III原型装置上利用8路6400 J/1 ns激光注入Φ1100μm×1850μm的黑腔内产生约200 e V的高温辐射场均匀辐照填充氘氘燃料的靶丸实现内爆.实验中,保持靶丸的内径一致,通过改变靶丸烧蚀层厚度的方式实现不同收缩比的内爆.通过闪烁体探测器、分幅相机等多套诊断设备获取了中子产额、X光bang-time(聚变反应产生X光时刻)、飞行轨迹、热斑形状等关键内爆参数.结合一维数值模拟表明:对于小收缩比内爆,受到非一维因素的影响小,其Y OC1D(实验测量中子产额与干净一维数值模拟计算结果之比)可以达到34%;对于中等收缩比内爆,受到非一维因素的影响显著,其Y OC1D仅仅为2.3%.

The plastic DD filled capsule implosion experiment is performed on Shenguang III prototype laser facility. One- dimensional hydrodynamic numerical simulations show that the implosion compression ratio can be controlled by chang- ing the capsule ablator thickness. In experiments, two types of capsules are studied and most of important implosion parameters are collected, such as neutron yield, X-ray bang-time, trajectory, and shape of hot core. The comparison between post-simulations and experimental results is performed. In our experiments, the neutron yield is 6.8 × 10^7 and YOCID reaches 34% for low compression ratio implosion; the neutron yield is 6.3 × 10^6 and YOC1D is only 2.3% for middle compression ratio implosion. Meantime, the shape of hot core obtains an extra higher Legendre partial （P2 is 18% and P4 is 5%）. On another side, the trajectory and bang-time are compared with simulations well.