激光聚变靶丸球面经纬迹线优化球度测量方法

Optimized sphericity measurement method for the latitude and longitude traces on the surface of ICF capsule

针对激光聚变靶丸表面3D全形貌的高精度测量与评价难题,提出一种基于激光差动共焦原理的靶丸球面经纬迹线优化球度测量方法。该方法采用经纬迹线划分方案提高形貌信息采样覆盖率,实现靶丸球面形貌高效高精度测量。首先,利用差动共焦测量系统对靶丸球面经纬迹线上二维圆周采样点进行精准定焦,获取二维轮廓信息;然后,利用精密三维位姿调整机构和正交回转轴系切换被测截面,获取覆盖靶丸全球面多条经纬迹线处的高度信息;最后依据建立的靶丸球面经纬迹线三维坐标转换模型,采用最小二乘算法对靶丸球度进行高精度评定,并对靶丸表面进行形貌重构。实验结果表明:测量57条迹线,被测靶丸的球度误差为1.946μm。该方法为靶丸表面全形貌高精度测量与评定以及定性观察提供了可行性方案。

It is difficult to implement high-precision measurement and evaluation of the full surface topography of inertial confinement fusion(ICF)capsule.In this article,an optimized sphericity measurement method is proposed,which is for the latitude and longitude traces based on the principle of laser differential confocal.Firstly,the method uses the measurement system to achieve precise focusing of the circumferential sampling points on the capsule surface.Secondly,the measured cross section of the capsule is switched by using the precise 3 D adjustment mechanism and an orthogonal rotary system.The height information at the latitude and longitude traces of the whole capsule spherical surface is obtained.Finally,the 3 D coordinate transformation model of complete coverage mode is formulated.The least square algorithm is used to evaluate the sphericity of the capsule,and the 3 D surface of the capsule is reconstructed.The experimental results show that the sphericity error of the measured capsule is 1.946μm when 57 traces are measured.This method provides a feasible scheme for the high-precision measurement and evaluation,qualitative observation of the full topography of the ICF capsule surface.