激光聚变靶丸球度测量与评定

Sphericity measurement and evaluation for laser fusion target

为了解决激光聚变靶丸表面形貌高精度测量与评定的难题,提出一种激光差动共焦靶丸球度测量与评定方法,该方法利用激光差动共焦测量系统的轴向响应曲线的过零点与其物镜焦点位置相对应这一特性实现对靶丸表面的定焦,通过将靶丸在两个正交的方向上分别旋转,测量并获取靶丸表面的数个截面,实现靶丸表面全形貌测量,利用最小区域球度评定算法,建立靶丸球度评定的三维模型,对靶丸表面形貌进行定量评定。搭建实验装置对靶丸表面进行采样测量,评定结果显示,该方法的测量重复性为0.15μm,为靶丸表面形貌测量与评定提供了一种可行方案。

In order to solve the difficulty of high precision measurement and evaluation of the surface morphology of laser fusion target, a laser differential eonfocal sphericity measurement and evaluation method for the laser fusion target is proposed. This method uses the property that the zero-crossing point of the axial response curve of the laser differential confocal measurement system corresponds to the focus point position of the objective lens to realize the target surface focusing. Through rotating the target in two orthogonal directions respectively, a number of cross-sections of the target surface are measured and acquired; and the whole morphological structure measurement for the target is achieved. The minimum zone sphericity evaluation algorithm is used to establish the three-dimensional model for the target sphericity evaluation, the quantitative evaluation of the target morphological structure is conducted. Based on the method, an experiment system was built to perform the morphological structure measurement of the target surface. The evaluation results show that with the proposed method the measurement repeatability reaches 0.15 μm, which provides a feasible scheme for the morphological structure measurement of fusion target.