针对激光聚变靶丸内表面轮廓高精度无损测量的迫切需求, 研制了一套激光聚变靶丸内表面轮廓测量系统。该系统通过最小二乘算法(LSC)计算出靶丸回转偏心量, 并利用偏心调整台对靶丸偏心进行自动快速调整; 然后, 系统软件控制气浮回转轴承驱动靶丸旋转, 利用激光差动共焦传感器(LDCS)轴向响应曲线过零点及光线追迹算法精确计算出靶丸内表面轮廓上每个采样点的几何位置; 最后, 对靶丸内轮廓测量数据进行LSC评定得到其圆度信息。实验证明, 靶丸回转偏心的自动调整时间可达22 s, 当采样点分别为1 024, 2 048及4 096时, 靶丸内轮廓测量时间分别可达10, 20及40 s, 且圆度测量标准差可达19 nm(1 024点)。该系统实现了靶丸回转偏心的自动快速调整及其内轮廓的高精度、无损、快速、自动测量。

A novel magnetic levitation support method is proposed, which can relieve the perturbation caused by traditional support methods and provide more accurate position control of the capsule. This method can keep the perfect symmetry of the octahedral spherical hohlraum and has the characteristics in stability, tunability and simplicity. It is also favorable that all the results, such as supporting forces acting on the superconducting capsule, are calculated analytically, and numerical simulations are performed to verify these results. A typical realistic design is proposed and discussed in detail. The superconducting coating material is suggested, and the required superconducting properties are listed. Damped oscillation of the floating capsule in thin helium gas is discussed, and the restoring time is estimated.

发展了背光阴影成像技术, 用于诊断透明ICF冷冻靶冰层内表面质量。分析了单层球壳阴影图像中形成亮环的物理机制。用光学追迹软件Tracepro模拟产生了透明单层球壳的阴影图像, 用于研究亮环位置与球壳厚度及折射率的关系。建立了背光阴影成像实验装置, 获得了透明单层球壳具有明显亮环的实验阴影图像。编制了阴影图像处理软件, 获得了靶丸内表面1维功率谱曲线, 并据此计算出靶丸内表面均方根粗糙度。理论分析、软件模拟及实验研究均表明, 背光阴影成像技术是透明冷冻靶冰层内表面质量的有效诊断方法。

利用Gifford-McMahon(G-M)制冷机提供低温源,研制了平面低温冷冻靶系统。该系统最低温度可以达到10 K,制冷功率随温度降低而降低,制冷速率可控。其中,在18.6 K其制冷功率可以达到6.5 W;在14 K其制冷功率为3 W。利用该系统,初步开展了氩、氢的冷冻实验,并研究了温度对激光惯性约束聚变靶丸结构的影响。获得了氩、氢平面低温冷冻靶,并观察到了低温诱导聚变靶丸形变现象。