激光聚变靶丸内表面轮廓测量系统的研制

Development of inner-surface profile measurement system for ICF capsule

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22s,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40s,且圆度测量标准差可达19nm(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。

Considering the urgent demand for high-precision and nondestructive measurements of a Inertial Confinement Fusion(ICF)capsule,an inner-surface profile measurement system for an ICF capsule was developed in this study.First,the system used a Least Square Circle(LSC)algorithm to calculate the capsule′s eccentricity and adjusts it automatically and quickly using the eccentricity adjustment table.The system then controlled via software an air-bearing shaft to drive the capsule rotation,and it used the zero-crossing point of the axial response curve of a laser differential confocal sensor and a ray tracing algorithm to calculate the geometric position of each sampling point on the capsule′s inner-surface profile.Finally,the roundness value of the inner profile was evaluated using LSC.Experimental results show that the eccentricity adjustment time can reach 22 s,and the inner profile measurement time can reach 10,20,and 40 s,which correspond to the sampling points of 1 024,2 048,and 4 096,respectively.In addition,the standard deviation of the inner profile roundness is shown to be as high as 19 nm(1 024 points).The system realizes an automatic rapid adjustment of the capsule′s eccentricity and a high-precision,nondestructive,rapid,and automatic measurement of the capsule′s inner profile.