Abstract: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 3D 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 3D coordinate transformation model of complete coverage mode is formulated. The least square algorithm is used to evaluate the sphericity of the capsule, and the 3D surface of the capsule is reconstructed. The experimental results show that the sphericity error of the measured capsule is 1. 946 μm 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.